A bomb attack on a Syrian government building near Damascus has killed 31 people, according to the Syrian Observatory for Human Rights.
Four generals were among the dead, the activist group said.
The explosives are thought to have been placed in the basement, meaning opposition fighters were able to breach security to get into the building.
There has been no confirmation of the attack by state media, or by government officials.
But Damascus has experienced increasing violence recently, as clashes between government forces and rebels in the suburbs intensify.
Three people were killed on Thursday by bombs and mortar fire near the historic Old City of Damascus.
On Monday the driver of a school bus and four children died when a mortar hit their vehicle.
Sunday’s explosion happened in the suburb of Harasta, north-east of the capital.
The Syrian Observatory for Human Rights – a UK-based activist network – said it was not clear what type of bomb was used, but that the force of the blast completely levelled the building.
“Only the night staff were on duty when the explosion occurred. If the bomb had gone off an hour before, there could have been up to 200 dead,” the group’s head, Rami Abdel Rahman, told Reuters news agency.
Fleeing the fighting
As well as the clashes around Damascus, there has also been fierce fighting north of the capital, in Qara, near the border with Lebanon.
Government forces tried to storm rebel positions in the town, the Observatory said.
Thousands of Syrians have been pouring over the border to Lebanon in the past two days, taking shelter from the clashes, according to UN and local officials.
The UN says more than 100,000 people have been killed since the uprising against President Bashar al-Assad began in 2011.
More than 2.2 million Syrians have fled to neighbouring countries while an estimated 4.25 million have been displaced internally.