The bloody conflict in Syria spilled across two borders Monday, killing a cameraman in Lebanon and wounding at least five people in a refugee camp in Turkey as guns fired across the tense frontiers, authorities said.

The violence came as a UN-brokered peace plan all but collapsed and bolstered fears that the uprising could spark a broader conflagration by drawing in neighbouring countries.

Ali Shaaban, a cameraman for the Al Jadeed television station, was filming in Lebanon's northern Wadi Khaled area when a bullet pierced his chest, Lebanese security officials said. The gunfire came from the nearby Syrian village of Armouta, the officials said.

Shaaban, who was born in 1980, died on the way to the hospital, the officials said on condition of anonymity in line with regulations.

His colleague, reporter Hussein Khreis, said the team heard heavy gunfire around them from all sides, "falling like rain." Shaaban was inside a car when he was struck, Khreis said.

A Lebanese civil defence ambulance is seen at the site where a television team was shot near Wadi Khaled village in northern Lebanon Monday. A cameraman for Lebanon's Al-Jadeed television channel was shot dead near Lebanon's northern border with Syria, the television channel said. (Roula Naeimeh/Reuters)

"If you see the car you would think it was in a war zone," Khreis said on Al Jadeed TV. "It is completely destroyed from the bullets."

He said they waited for more than two hours for the army and some residents to come and pull them out to safety.

"I ask forgiveness from Ali's family because I couldn't do anything for him," he said, breaking into tears.

Earlier Monday, Syrian forces fired across the border into a refugee camp in Turkey, wounding at least five people, authorities said.

Turkish security forces were reinforced in the well-marked border area following the attack, state television said.

Gaziantep Gov. Yusuf Odabas said, meanwhile, that two of 13 Syrians who had been wounded in clashes inside Syria and were brought to Kilis for treatment earlier Monday have died.

More than 24,000 refugees have crossed from Syria into Turkey.

This undated photo provided by the family shows Ali Shaaban, a Lebanese television cameraman who was killed Monday while working on the Syria-Lebanon border. (Family of Ali Shaaban/Associated Press)

Even its allies, China and Russia, stepped up pressure on the Syrian regime to stop the fighting. President Bashar al-Assad's foreign minister is in Moscow on Monday, and it appears it's up to the Russians to try to keep the peace plan alive.

The peace plan, brokered by former UN secretary general Kofi Annan on behalf of the United Nations and the Arab League, appeared to be on the verge of collapse.

With the ceasefire set to take effect Tuesday, the weekend was particularly violent, even for Syria, with reports that 180 people were killed, said the CBC's Middle East correspondent, Derek Stoffel.

"Syrian forces were supposed to be preparing for a ceasefire, the first stage to take effect less than 24 hours from now," he said.

"Instead, video posted online shows the regime's military pounding the city of Homs. One activist says mortar rounds were falling 'like rain.'"

UN Secretary General Ban Ki-moon said in a statement he "strongly deplores" the cross-border shootings. Ban also reiterated the UN's demand that Syria immediately cease all military actions against civilians and fulfil all of its commitments made to Annan.

"The timeline for the complete cessation of violence endorsed by the Security Council must be respected by all without condition," Ban said Monday.

Mass executions in Homs, Idlib

At the last minute, the Syrian government raised new demands, saying Sunday it will only withdraw its troops if there are written guarantees that the opposition would also lay down its arms first.

This unverified image obtained on April 6 shows a mass burial of people allegedly killed in recent shelling in Taftanaz, Syria. Human Rights Watch says there have been several mass executions in the country. (Associated Press)

That was almost immediately rejected by the Syrian National Council, a main opposition group.

A leading international human rights group said Monday that Syrian forces have summarily executed more than 100 people, most of them civilians.

The report by Human Rights Watch said this includes several mass executions in the provinces of Homs and Idlib.

The New York-based group says it only included cases corroborated by witnesses, but has received more reports of similar incidents. The executions took place over the past four months, mostly in March.

The UN says more than 9,000 people have been killed in Syria since the anti-Assad revolt began 13 months ago with peaceful protests. The uprising has turned increasingly violent in recent months in the face of a brutal government crackdown.

With files from CBC News