A car bomb has killed nine people at a Syrian military post in the eastern city of Deir al-Zor.
The government said the attack was the latest proof that an uprising against President Bashar al-Assad was a foreign plot.
The official SANA news agency said the blast had been the work of a suicide bomber and had also wounded about 100 people, including guards, at what it called military installations.
There was no independent verification of the claims from Syria, which allows little or no access to foreign journalists.
International pressure and a UN-backed peace plan has failed to quell Syria's turmoil.
French President Francois Hollande said today that the peace plan still had international backing, but Washington sounded a more aggressive note saying Mr Assad had to leave power.
Syrian state television broadcast footage of smoke rising over Deir al-Zor, pools of blood amid rubble, the damaged facades of buildings and twisted, smoking vehicles.
Opposition activists said the target was an intelligence base.
"It seems like a well-planned attack. The explosion hit the least guarded rear gate of the Military Intelligence complex ... where the operatives keep their cars," said one activist in Deir al-Zor.
State television called the blast part of a campaign funded by Saudi Arabia and Qatar to topple Mr Assad.
The Sunni-led Gulf powers have called for military help for the Free Syrian Army, a loosely organised force of defecting soldiers and protesters formed in response to Assad's crackdown on what began 14 months ago as a peaceful uprising.
Syrian television said UN staff who are supposed to be monitoring an internationally brokered ceasefire had inspected the site.
The UN/Arab League peace plan drawn up by Kofi Annan aims to mark a political path out of the violence in Syria.
Mr Hollande said leaders of the G8 countries, meeting at Camp David, had agreed to continue supporting Mr Annan's Syrian peace efforts.
"I insisted that all the participants support Kofi Anan's mission so that observers can provide protection of the Syrian people from their leaders," Mr Hollande said.
However, the White House said Syria's violence would not end without a political changeover, adding that external monitors and a ceasefire would not be sufficient to address the problem.