The UN says there are 2.5 million internally displaced refugees in Syria, and thousands fleeing into nearby countries.
Latest events: A UN official said on March 14 that the number of registered Syrian refugees has risen by more than 10 per cent in one week.
The number of refugees since the start of the war was said to have reached one million.
United Nations refugee agency chief, António Guterres, said early in March that those numbers could increase by up to two or three times by the end of the year.
Those who are part of the exodus are mostly fleeing to Lebanon, Iraq, Turkey, Egypt and North Africa.
The UN estimates that around 70,000 people have been killed as a result of the two-year conflict.
Over half of the four million people displayed because of the war in Syria are 18 years old or younger, a "lost generation" according to a March 12 report from UNICEF.
The report, titled Syria’s Children: A Lost Generation, estimated that out of the two million displaced outside of Syria, children make up approximately 40 per cent, adding that current numbers are likely "much higher."
Also on March 12, a rocket attack near Damascus killed a European Union adviser.
Ahmad Shihadeh, 32, a policy officer with the EU delegation in Syria, lived in the Damascus suburb of Daraya. Shihadeh’s death marked the first of an EU employee during the civil war.
The violence continued in March as Syrian warplanes bombed the northern city of Raqqa hours after rebels had reportedly taken it.
Twenty-one UN peacekeepers were finally freed by rebels in southern Syria on March 9, after being held hostage for four days.
Some said the incident highlighted how disorganized the rebel movement is and raised concerns about how the UN will operate in this area in the future.
On Feb. 24. Walid Musallem, Syria's foreign minister, said the government would be willing to talk with the opposition. That same day, rebels attacked a government complex near Aleppo.
It was reported that Bashar al-Assad’s forces fired missiles into residential areas of Aleppo, killing an estimated 141 people in what the Human Rights Watch called a "new low" for the regime.
Rebels claimed on Feb. 22 they were again the target of a rocket attack when three missiles landed in neighbourhoods in Aleppo.
On Jan. 14, an air attack by the Syrian military against rebel forces struck a house outside of Syria's capital, Damascus. Thirteen were killed in the suburb, including eight children, the Associated Press reported.
This attack followed another on Jan. 13, when a government barrage killed 45 people in the Damascus area.
The attacks were considered some of the heaviest in the region since the Syrian government initiated an offensive in November 2012 to try and remove rebels from the outskirts of Damascus.
On Jan. 13, a shell fired from Syrian military landed in an empty field in Turkey. No one was hurt, but last November, Turkey warned it would retaliate if attacked. In December, NATO announced it would deploy Patriot missiles along Turkey's border with Syria in order to protect the NATO ally from the conflict. The missiles are scheduled to become operational in late January.
After not making any public appearances for six months, Syrian President Bashar al-Assad spoke to a Damascus audience in early January, in which he outlined a peace place that would allow him to remain in power and continue to fight the rebels.
Also in early January, the United Nations' World Food Programme reported it was unable to help one million Syrians who are going hungry.
The general who heads Syria's military police reportedly defected and joined the uprising against Assad's regime on Dec. 26, one of the highest-profile walkouts by a serving security chief during the uprising, a pan-Arab TV station reported.
Opposition forces claim to have taken control of several strategic sites in recent weeks despite the use of heavier weapons by pro-Assad fighters, including Scud-type missiles, according to NATO Secretary-General Anders Fogh Rasmussen.
The opposition has also been gaining international support. In early December, U.S. President Barack Obama declared the country's main opposition group the sole "legitimate representative" of the country's people.
The National Coalition of the Syrian Revolutionary and Opposition Forces was established at a meeting in Doha on Nov. 11, bringing together the vast majority of groups that have been calling for Assad to step aside. This marked a major turning point in the conflict.
Despite the apparent shift in momentum toward the opposition forces — both diplomatically and on the ground — the fighting shows no sign of letting up and Syrians continue to flee into neighbouring countries.
The opposition had been fractured and comprises various groups.
The largest armed contingent is a loose affiliation of armed opponents of the regime and defectors from the Syrian military called the Free Syrian Army. Its leaders said Sept. 21 that they had moved their command centre from Turkey to Syria with the aim of uniting rebels and speeding up the fall of Assad's regime.
Casualties and refugees
A rising tide of civilians fleeing Syria's violence is hitting four neighbouring countries — Turkey, Jordan, Lebanon and Iraq. More than 120,000 Syrians, mostly women and children, have sought refuge in Turkey since the start of the conflict.
The violence in Syria crossed a symbolic threshold on July 15, when the international Red Cross formally declared the conflict a civil war, a status with implications for potential war crimes prosecutions.
Many human rights groups say many atrocities have been committed during the conflict.
A video circulated Nov. 2 appeared to show Syrian rebels killing a group of captured soldiers, spraying them with bullets as they lay on the ground. Human rights groups said the gunmen may have committed a war crime.
A report released Sept. 25 by the U.K. charity Save the Children compiled first-hand accounts from Syrian refugee children who fled the war-torn country who say they were subjected to atrocities. A UN report released June 11 includes Syrian government forces and their allied shabiha militias for the first time on a list of 52 governments and armed groups that recruit, kill or sexually attack children in armed conflicts.
Human Rights Watch said July 11 it had found evidence that the Syrian government had fired cluster bombs. The Syrian government also faced allegations July 3 of systematic detainment and torture of its citizens, in a report by the group Human Rights Watch based on more than 200 interviews with former detainees and defectors.
Opposition forces have been trying for months to oust Assad, a former ophthalmologist who assumed the Syrian presidency after the death of his father, Hafez, in 2000.
The Assad family has governed Syria since 1971, when Hafez al-Assad seized power in a bloodless coup. The younger Assad was thought to be more reform-minded than his father, but the brutal military response to the current uprising suggests that Bashar will do everything in his power to maintain the status quo.
The ruling Baath Party promoted a socialist and Arab nationalist vision. Syria was seen primarily as a secular state where religious minorities were tolerated prior to the uprising, but the government did not tolerate dissent.
Population: 22,517,750 (July 2010 estimate)
Area: 185,180 sq. km
Borders: Iraq, Israel, Jordan, Lebanon and Turkey
Languages: Arabic is the official language, but Kurdish, Armenian, Aramaic and Circassian are widely used. French and English are used to a lesser extent.
Religion: 74 per cent Sunni Muslim; 16 per cent Alawite, Druze and other Muslim sects; 10 per cent Christian.
Government: Republic under authoritarian regime.
Source: CIA World Factbook 2010
The international community has pushed to end the ongoing violence.
The UN General Assembly voted overwhelmingly on Feb. 16, 2012, for a non-binding resolution backing an Arab League plan calling for Assad to step down and strongly condemning human rights violations by his regime.
Former UN secretary general Kofi Annan was appointed the joint United Nations-Arab League envoy on the Syrian crisis on Feb. 23, 2012, with a mandate to bring an end to the violence and promote a peaceful political solution.
The UN Security Council has also been working on efforts to halt the ongoing civil unrest, but has remained deadlocked.
The council has attempted to push through three Western-backed resolutions aimed at pressuring Assad to enter negotiations on a political transition. Syrian allies Russia and China have vetoed these resolutions, paralyzing the UN's most powerful body.
Annan's peace plan never took hold and the work of UN monitors was stopped in the summer due to escalating violence. Annan stepped down from the post on Aug. 2.
Lakhdar Brahimi took over as UN envoy to Syria on Aug. 17. He has continued Annan's work to try and broker a peace deal, without success.
The UN sent a group of observers into Syria in April 2011 to monitor a five-day ceasefire as part of a six-point plan brokered by then-envoy Annan.
However, the truce never took hold, and most of the observers were confined to their hotels amid the escalating violence.
The Security Council decided Aug. 16 to let the UN monitoring mission's mandate expire, but said it will back a new civilian office to support the UN and the Arab League in their efforts to end the conflict that's killed more than 40,000 people.
As well, about 60 observers from the Arab League were allowed into Syria from Dec. 27, 2011, to Jan. 19, 2012, but were prevented from visiting many of the most troubled spots and from monitoring the situation independently. The CBC's Susan Ormiston reported from Damascus on Jan. 11, 2012, that, "there is a tension and conflict between the Syrian government and the Arab League monitors, and the opposition hasn't been very satisfied with their work, either."
The League withdrew its monitors from Syria on Jan. 28, 2012, because of the increasing violence and obstruction from the regime.
The ongoing violence has sparked international outrage, prompting some nations to pull out their ambassadors from Syria and expel Syrian diplomats from within their borders.
On Feb. 6, the U.S. pulled its embassy staff from Damascus. The U.S. has also imposed sanctions, freezing all Syrian assets in the U.S. and banning the import of all Syrian petroleum and petroleum products.
Other countries, including those of the European Union, have followed suit. The EU has placed sanctions on Syrian people and organizations and has banned the import of Syrian crude oil. The sanctions include visa and travel bans, the freezing of assets, prohibitions on the purchase of gold, precious metals, diamonds and other types of trade and a ban on cargo flights from EU countries to Syria.
International outrage against Syria intensified on May 29, 2012, as France, Britain, Germany, Italy, Spain, Canada and Australia expelled Syrian diplomats in response to a massacre of 108 civilians, including women and children, in the town of Houla. Witnesses blamed the house-to-house killings on pro-government militias known as shabiha. Turkey, Syria's neighbour and a former close ally, and Japan joined the co-ordinated protest May 30.
Obama said Aug. 20 that the U.S. would reconsider its opposition to military involvement in the civil war if Assad deploys or uses chemical or biological weapons.
Syria barred a string of U.S. and European diplomats on June 5, saying they were "no longer welcome." Damascus took a "reciprocal measure" against ambassadors from the U.S., Britain, Turkey, Switzerland, Germany, Canada, Bulgaria, Belgium, France, Italy and Spain.
Syrian allies have also spoken out against the regime. Iranian President Mahmoud Ahmadinejad said May 31 that those responsible for the massacre of more than 100 people in Houla should be punished. It was an unusually harsh criticism from an ally of Syria.
A former ally of Syria, Turkey condemned Assad on Dec. 22, 2011, for turning his country into a "bloodbath." On Nov. 15, 2011, Turkey called on the Syrian government to end the violence and added that it was cancelling oil exploration plans in the country. By October 2012, an estimated 100,000 Syrians had fled the fighting into Turkey, with more seeking refuge in Lebanon.
The Arab League approved sanctions against Syria on Dec. 3, 2011, barring several Syrian officials — but not Assad — from travelling to the League's member nations. The group also agreed to a list of strategic goods that would be exempted from a trade ban to avoid harming the Syrian people and also ordered a 50 per cent reduction in flights to Syria.
On Feb. 7, 2012, the six nations of the Gulf Co-operation Council pulled their ambassadors from Syria, because of Assad's refusal to accept Arab attempts to end the country's bloodshed.
Canadian Foreign Affairs Minister John Baird said Aug. 15, 2012, that Canada has changed course and will not move forward with a plan to give $2 million to a Syrian-Canadian group for medical supplies.
Canada closed its embassy in Syria on March 5, 2012. It has imposed sanctions on Syria, including a ban on the export of software for the monitoring of telephone and internet communications, a travel ban on those associated with the regime, freezing Syrian government assets and prohibiting most Canadian trade with Syria.