Suicide car bombings ripped through a Syrian government base in a southern city on Saturday, killing at least 20 soldiers, an opposition group said, the latest in a series of explosions targeting regime forces and symbols of state security across the country.
The explosions in Daraa were followed by clashes between regime forces and rebels fighting to topple President Bashar Assad, activists said.
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 morphed into a civil war after rebels took up arms in response to the regime's crackdown.
The Britain-based Syrian Observatory for Human Rights, which relies on a network of activists on the ground, said two suicide bombers drove their explosives-laden cars into a military encampment behind the officer's club in quick succession. It said at least 20 soldiers were killed, most in the second explosion.
Other activists described explosions that targeted the high security area but didn't say they were suicide attacks. State-run news agency SANA reported triple car bombings in Daraa that killed seven civilians and wounded several others.
The Syrian government rarely provides death tolls for security forces, and the discrepancy could not be reconciled or independently verified.
"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, and heavy shooting could be heard from the area for about 10 minutes after the explosions.
Bombings targeting state security institutions have become frequent in recent months, frequently hitting military intelligence branches in Damascus and other cities. 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 defence minister.
There was no immediate claim of responsibility for Saturday's attack in Daraa, but Jabhat al-Nusra, an al-Qaida-inspired extremist group that is fighting alongside the rebels, has said it was responsible for similar bombings in the past.