Twin car bombs struck intelligence and security buildings in the Syrian capital Damascus, killing at least 27 people and wounding nearly 100, according to state media.
Syrian state television said explosives were detonated on Saturday outside buildings for the aviation intelligence department and the criminal security department. It showed pictures of destroyed vehicles and bloodstains on the city's streets. Reports quoted the country's health minister as saying at least 27 people were killed.
Video from the blast at the intelligence centre showed the front of the building blown away.
State TV described the explosions as the work of terrorists, but no one has claimed responsibility for the attacks.
There have been similar bombings in recent months. Dozens of people were killed in suicide bombings that struck Damascus in late December and the city of Aleppo last month.
An activist and spokesperson for the Syrian Revolution General Commission in the city of Homs on Saturday accused the Assad regime of setting off explosives in Damascus and then blaming the opposition movement.
In an interview with CBC News, Abu Abdu al-Homsi denied opposition involvement.
"We are peaceful protesters all around Syria," he said.
He also claimed the government brings bodies to the scene of explosions.
"They made so many explosions all around in Syria and different cities, in Damascus and in Aleppo. And then they bring bodies, which are prisoners, killed by the regime, bring them to the place where the explosion happened, and then they say, okay, these are terrorists," al-Homsi said.
The United Nations says more than 8,000 people have been killed and some 230,000 forced to flee their homes since the uprising to oust President Bashar Assad began last March.
No weapons for Syria through Iraq
A spokesman says Iraqi leaders have told Iran it cannot ship weapons to Syria through Iraq.
Iraqi government spokesman Ali al-Dabbagh on Saturday said the Iranian ambassador in Baghdad has been warned against shipping arms through Iraq's borders or airspace.
Diplomatic efforts have so far brought no result in ending the conflict, which slides closers to civil war.
Syria has told international envoy Kofi Annan in a letter obtained Saturday by The Associated Press that it is "keen to end violence" but insists that armed opposition groups give up their weapons first.
The Syrian response falls far short of U.S. and European demands that Syrian forces stop fighting first — and even Russia's insistence that both sides lay down their arms simultaneously.
But it does leave the door open for talks, and Annan is sending a team to Damascus on Sunday to continue discussions on implementing his proposal to end the year-long conflict. Annan said Friday that if the team makes sufficient progress he will consider returning to Damascus, where he held two rounds of talks last weekend with President Bashar Assad.
The Syrian letter asks Annan, the joint UN-Arab League envoy, "to provide guarantees to the Syrian government that the armed groups will cease all armed aggressions and give up their weapons to the dedicated authorities in exchange of a full pardon."