Syrian warplanes hit a rebel-held district of Aleppo on Tuesday, an AFP journalist said, as fighting raged in several neighbourhoods of the embattled northern city.

Government forces also shelled two flashpoint districts of the city and a hospital in the east which also been hit only two days ago and was largely empty of patients and medical staff, the journalist said.

A MiG jet fired several times on the central district of Bab al-Nasr, the journalist said, adding that the southwestern districts of Saif al-Dawla and Salaheddin were also shelled.

At the hospital in the rebel-controlled eastern district of Shaar, three patients were being treated for gunshot and shrapnel wounds in a small, cramped emergency room.

One had been shot twice by a sniper, hospital staff said, as he walked to work.

The hospital remains standing but on the third floor, a hole in the wall flooded the corridor and a room with daylight and debris lined the beds. Outside, Free Syrian Army fighters swept glass from the streets.

The renewed violence came as a pro-government daily warned that the army's capture last week of Salaheddin was just a "first step" in the retaking of all opposition areas in the city, after regime forces advanced on neighbouring Saif al-Dawla on Monday.

Government forces also shelled several suburbs of Damascus, while security forces carried out a second day of raids in the capital, the opposition monitoring group the Syrian Observatory for Human Rights said.

Tuesday's violence has so far claimed the lives of 63 people, the Britain-based watchdog said, after a bloody day in which 160 people were killed nationwide.

Among those wounded in Aleppo was a journalist working for state news agency SANA.

Government forces also pounded the rebel-held eastern districts of Sakhur, Hanano and Shaar, the Observatory said.

The pro-government Al-Watan said the army "has deployed but a fraction of its troops... to control Salaheddin, whose liberation is just one step towards the control of the rest of the areas under the influence of the insurgents".

"Army units continue to encircle the city and block the insurgents' supply lines," the paper said.

Control of the city is seen as pivotal to the outcome of the conflict, which has now claimed at least 23,000 lives since March last year, Observatory director Rami Abdel Rahman told AFP.

In the capital Damascus, residents fled the Qaboon neighbourhood, fearing a major military onslaught, as security forces raided the districts of Midan in the south and Shaghur in the centre, the Observatory said.

According to an AFP journalist, security forces also swept the southeastern district of Tabbaleh, while the army set up checkpoints at the entrances to Midan and closed off streets to traffic.

Outside the city, government forces shelled the suburbs of Qudsaya and Daraya, while elsewhere in Damascus province, a civilian and defecting soldier were killed in Al-Tal town, the Observatory said.

The opposition Syrian National Council described Al-Tal as a "disaster area" after five days of shelling and urged "all able citizens" to provide aid, especially food and medical supplies.

In Muhasen in the eastern Deir Ezzor province -- where rebels claimed they downed a fighter jet Monday -- fierce clashes broke out, according to Local Coordination Committees, a network of activists on the ground.

Elsewhere in Deir Ezzor, six members of one family were killed in shelling, while four civilians were killed in northwest Idlib province and a woman was shot dead by a sniper in southern Daraa province, the Observatory said.