Warplanes bombed a Palestinian refugee camp in south Damascus on Sunday for the first time in Syria's 21-month uprising, as the army escalated its efforts to suppress the rebellion in the capital.

The Syrian Observatory for Human Rights said the air strike killed at least eight civilians at Yarmuk camp, which has been hit by intermittent violence during the past few months.

The raid came as President Bashar al-Assad's forces used fighter jets against rebel positions in the provinces of Hama and Aleppo, where rebels stepped up a bid to seize a military academy.

Analysts say the Assad regime is still standing firm despite predictions by Western officials, and even a top Russian diplomat, of its imminent fall, and the fact rebel fighters now hold vast swathes of territory.

"Warplanes staged an air strike on an area near Al-Bassel hospital... in Yarmuk camp," the Observatory said.

Residents told AFP that a missile hit the Abdel Qader Husseini Mosque in the heart of the camp.

The mosque was acting as a makeshift shelter for some 600 people forced to flee their homes in nearby districts engulfed in violence.

Amateur video posted online by activists in the camp showed broken glass strewn on the ground by the mosque, and several bloodied bodies laid out at the entrance.

"There is a state of real war in the camp now," Yarmuk resident Abu Mohammed told AFP by Internet.

"There are intense battles between the Free Syrian Army and the Popular Front for the Liberation of Palestine-General Command," a hardline Palestine militant group that has long been a Damascus ally.

The air strike on Yarmuk was Sunday's sixth on flashpoint districts of south Damascus, the Observatory said.

Fighter jets also bombed the nearby districts of Al-Hajar al-Aswad and Assali, scene of intense fighting between troops and rebels.

"The army feels it has to step up its campaign to suppress the insurgency in south Damascus, and that it cannot fight off rebels without resorting to air power," said the Observatory's Rami Abdel Rahman.

The escalating violence came a day after Iran's armed forces chief of staff warned Turkey over its plans to deploy US-made Patriot missiles near Syria, saying the move was part of a Western plot to "create a world war".

"The Western countries seeking to deploy the missile batteries on the Turkey-Syria border are devising plans for a world war. This is very dangerous for everyone," General Hassan Firouzabadi said.

NATO has approved Turkey's request for Patriot missiles to bolster its restive border defences, with Germany, the Netherlands and the United States agreeing to provide the missile batteries.

But both Russia and Iran, the most powerful allies of the Assad regime, are opposed to the move.

Moscow declared on Friday it had not and would not change its stance on Syria, a day after Deputy Foreign Minister Bogdanov said Damascus was "losing more and more control" and that it was not excluded Assad could lose the war.

Russia has so far refused to turn against Assad's regime despite the conflict.

On the ground, violence raged as at least 19 people were killed in air strikes across the country, among them six children, said the Observatory, which relies on a network of activists and medics for its information.

In the northern province of Aleppo, eight people including three children, died in air strikes on the town of Safira.

In the central province of Hama, three children were killed in air raids on the town of Kfar Zeita.

Just south of Kfar Zeita, six civilians were killed in shelling on Latamneh village and 23 people, including 15 civilians, died in clashes and army bombardments on the town of Halfaya.

Separately, rebels clashed with troops near an important military academy in Mulsimiyeh just north of the embattled city of Aleppo, the Observatory said.

The watchdog gave an initial toll of 52 people killed nationwide in Syria, adding to the total of more than 43,000 killed since the start of the uprising in March last year.