BEIRUT (AP) -- Twin explosions set off by a pair of suicide bombers shook a southern Syrian city on Saturday, killing and wounding dozens of regime forces, an activist group said.
The Britain-based Syrian Observatory for Human Rights, which relies on a network of activists on the ground, said the early morning blasts in Daraa targeted an encampment for government troops in the city. The Observatory said the explosions were followed by clashes between regime forces and rebels fighting to topple President Bashar Assad.
The state-run news agency SANA said the blasts caused multiple casualties and heavy material damage, but did not provide further details.
The southern city of Daraa was the birthplace of the uprising against Assad, which erupted in March 2011. The conflict began largely with peaceful protests against Assad's rule but turned bloody after rebels took up arms in response to the regime's crackdown.
The crisis has since morphed into a vicious civil war and in recent months, rebels have driven regime forces out of much of a pocket of northwestern Syria and are battling troops in several key cities and towns. The fight has also taken on dangerous sectarian tones between a mainly Sunni opposition and a regime dominated by Assad's minority Alawite sect, an offshoot of Shiite Islam.
"I heard two very loud explosions and a third smaller one followed by bursts of gunfire," said Mohammad Abu Houran, an activist in Daraa. He said the first two were likely car bombs and the third a mortar shell or rocket propelled grenade.
Abu Houran said black smoke could be seen over the high-security area, which was sealed off. Heavy shooting could be heard from the area for about 10 minutes after the explosions, he added.
Bombings targeting state security institutions have become frequent in recent months, and military intelligence branches in Damascus and other cities have been hit. Most dramatically in July, rebels detonated explosives inside a high-level crisis meeting in Damascus, killing four top regime officials, including Assad's brother-in-law and the defense minister.
Rami Abdul-Rahman, the Observatory's head, said at least 20 soldiers were killed in Saturday's twin blasts, but the claim could not be independently verified.
The targeted area is considered a security zone that houses a branch of the country's Military Intelligence as well as an officer's club where dozens of regime forces are based. Around 30 tanks that regime forces use to shell Daraa and surrounding areas are also stationed in a nearby stadium, activists said.
Activists say more than 36,000 people have died in Syria during the nearly 20-month-old conflict.
The Daraa explosions come a day after as many as 11,000 people were said to have fled Syria over just 24 hours, to escape fierce fighting between rebels and government forces -- the latest surge of refugees fleeing the civil war.
The flood of Syrians into neighboring Turkey, Jordan and Lebanon was "the highest that we have had in quite some time," said Panos Moumtzis, the U.N. refugee agency's regional coordinator for the region said Friday.
About 2,000 to 3,000 people are fleeing Syria daily, and the recent surge brings the number registered with the UNHCR to more than 408,000, said Moumtzis.
The largest flow into Turkey came from the fighting at Ras al-Ayn in the predominantly Kurdish oil-producing northeastern province of al-Hasaka, where rebels were fighting government forces.