Syrian army helicopters dropped explosives-laden barrels on a camp for the displaced near Aleppo in the north on Monday, killing at least seven people, a monitoring group said.

And in shelling by rebels on a pro-regime neighbourhood in southeastern Damascus, at least six people were killed and 35 others wounded, the Syrian Observatory for Human Rights said.

The army used warplanes and helicopters to strike rebel areas near Damascus and in Homs province, in central Syria.

The Britain-based Observatory said that, among the seven killed near Sfeira in Aleppo province, were a child and two youths.

The bombing came as the army pressed a bid to secure a route linking Aleppo city to its bases in central Syria.

In Jaramana, southeastern Damascus, at least four civilians were among the six killed in a shelling attack by rebels.

"Thirty-five others were injured, some of them badly," said Observatory director Rami Abdel Rahman.

Hours earlier, state news agency SANA had reported a death toll of two in the shelling on Jaramana, which is home to a majority Christian-Druze population.

Nearby in Mleiha, days after advancing rebels took over key army positions, the air force unleashed a new air strike, said the Observatory.

Mleiha is important because it lies near pro-regime areas in the capital, which the army is trying to secure.

Violence also raged further south, with army shelling on Inkhil in Daraa province killing a man and a child from the same family, said the group.

In the central province of Homs, warplanes were deployed to strike rebels fighting troops in countryside areas that are important because they lie near the Lebanese border and just northeast of Damascus.