Twin suicide attackers targeted a police station in central Damascus killing at least 14 people and wounding more than 30, state television and a watchdog said.
The broadcaster screened images of blood and broken glass on the pavements near the scene of the blasts.
"The number of casualties after a twin suicide attack in Marjeh square has risen to 14 dead and 31 injured," said the channel, updating an earlier toll.
"The two suicide explosions took place near a police station," it said, adding that the blasts also caused material damage.
The channel broadcast interviews with civilians at the scene of the attack.
"God take revenge on those who are behind this... People were just sitting in their homes, or in their shops," said an unidentified shopkeeper, unable to hold back his tears.
"God take revenge against all those who are destroying this country," he said.
It's criminal... Look at the corpses, look at the blood," said another, who appeared to be in a state of shock.
The Syrian Observatory for Human Rights also reported the blasts, but put the toll higher at 15.
One of the blasts "was caused by a suicide bomb attacker who blew himself up inside the police station", said the Britain-based monitoring group.
"A second explosion took place just outside the police station," the group said, without elaborating on the nature of that blast.
"The number of casualties is expected to rise because several of the wounded are in critical condition," added the Observatory, which relies on a network of activists, doctors and lawyers for its reports.
Areas of central Damascus have suffered frequent bomb attacks through the course of Syria's 26-month war. Most attacks have subsequently been claimed by the jihadist Al-Nusra Front.