Damascus: Twin car bomb attacks on security posts in Syria's second city of Aleppo on Friday killed at least 28 people and wounded another 235, state television reported, citing the health ministry.

"The number of casualties from the two car bombs in Aleppo has risen to 28 dead and 235 wounded," said the ministry, adding that among the dead were soldiers as well as civilians, including children.

"In addition, there were four bags full of body parts of other victims," it said.

State television said the powerful mid-morning bombing attacks in the northern commercial hub were the work of "armed terrorist gangs."

It said a "suicide bomber in a car packed with explosives" launched an attack on a police station, flattening a nearby food distribution centre. The second bombing targeted an intelligence base.

But the rebel Free Syrian Army said the Syrian government itself was behind the bombings.

"This criminal regime is carrying out bomb attacks in Aleppo to steer attention away from what it is doing in Homs, Zabadani and elsewhere," said its spokesman, Colonel Maher Nouaimi, referring to the besieged central city.

The Syrian Observatory for Human Rights said at least 30 people were killed in the blasts.