Syria says twin suicide bombings in Damascus kill 44
State TV said suspected al-Qaeda militants had targeted two security service bases in the Kafr Sousa area.
But the opposition said the attacks - which came a day after Arab League observers arrived - were staged by the government to justify its crackdown.
Correspondents say the attacks mark a significant escalation of violence.
The Arab League team are tasked with monitoring whether the government complies with a peace agreement that orders all troops to withdraw from the streets, with the aim of ending the violence.
But human rights and opposition activists said the killings continued on Friday, with security forces shooting dead at least 12 civilians.
More than 5,000 people have been killed and thousands more detained since anti-government protests erupted in March, the UN says.