DAMASCUS — Syrian artillery gunners turned their sights on the rebel city of Rastan, killing seven civilians, monitors said, as the Red Cross delivered aid Sunday to refugees from the battered Baba Amr quarter nearby.

The aid distribution came as relief agencies waited for a third straight day for the go-ahead to enter Baba Amr, where hundreds of people are reported to have been killed and even more wounded in an almost month-long shelling blitz.

The shelling of Rastan -- which the Syrian Observatory for Human Rights said killed seven people, including four children, when a house was hit -- coincided with a call from China on all parties to "unconditionally" end the violence.

"Since dawn, the positions of deserters in the north of Rastan have been subject to intensive shelling," Rami Abdel Rahman, head of the Britain-based Observatory, told AFP.

Rebel fighters on February 5 declared Rastan "liberated" from President Bashar al-Assad's control, but since Homs was overrun by regime forces on Thursday, army deserters have been braced for an onslaught on Rastan and Qusayr, also near Homs.

Rastan is a strategic city as, like Homs, it falls on the main road linking Damascus with northern Syria.

The Observatory had on Friday reported 12 civilians, including five children, killed when a rocket slammed into a crowd of protesters in Rastan.

The latest deaths in Rastan raised to at least 10 the number of civilians killed across Syria on Sunday, according to the Observatory which also reported that a soldier was killed in the northeast province of Idlib.

AFP was not immediately able to verify the Observatory's reports due to restrictions on foreign journalists in Syria.

The rebels fled the Baba Amr section of Homs on Thursday in the face of a ground assault by regime forces following a shelling blitz since early February that the US-based Human Rights Watch said had killed some 700 people.

HRW said shells sometimes fell in Baba Amr at a rate of 100 an hour and that satellite images showed 640 buildings visibly damaged, but stressed that the real picture could be worse.

The Syrian authorities have been condemned by the international community for barring Red Cross convoys from entering Baba Amr to evacuate the wounded and deliver relief supplies.

The International Committee of the Red Cross (ICRC) said it delivered relief supplies on Sunday to refugees from Baba Amr in a nearby village of central Syria.

"We have started to distribute humanitarian aid in Abel village, three kilometres (two miles) from Baba Amr," ICRC spokesman Saleh Dabbakeh told AFP.

"Many refugees from Baba Amr are in Abel," he said, adding they were being supplied with food products and blankets.

Dabbakeh said a similar operation would take place in Inshaat, another district of Homs, while the ICRC and the Syrian Arab Red Crescent Society awaited the go-ahead from authorities to enter Baba Amr itself.

A seven-truck convoy organised by the aid groups has been waiting since Friday to enter Baba Amr, with the authorities saying they were being barred for their own safety because of the presence of bombs and landmines.

Amid international outrage over the delay, ICRC president Jakob Kellenberger has said: "It is unacceptable that people who have been in need of emergency assistance for weeks have still not received any help."

Opposition activists charge the regime's aim is to cover up its crimes in Baba Amr before allowing access to relief workers.

UN Secretary General Ban Ki-moon has demanded unconditional humanitarian access to Syrian cities, saying there were "grisly" reports of summary executions and torture in Homs, Syria's third largest city.

British photographer Paul Conroy, wounded in a rocket attack in Baba Amr on February 22 that killed two colleagues, said the bombardment of the besieged city amounted to a "medieval siege and slaughter," and denounced the Damascus government as "murderers."

The bodies of American journalist Marie Colvin and French photographer Remi Ochlik, killed in the rocket attack, were flown into Paris from Damascus on Sunday.

China, which twice joined Russia in blocking UN Security Council resolutions against Syria's lethal crackdown on dissent, urged an end to the violence.

Xinhua news agency cited a foreign ministry statement attributed to an unnamed official calling for dialogue between the Syrian regime and those expressing "political aspirations."

But the official reportedly added: "We oppose anyone interfering in Syria's internal affairs under the pretext of 'humanitarian' issues'."

The Syrian Observatory reported at least 44 people killed in Syria on Saturday, including 14 members of the security forces who died in clashes with deserters near Daraa, the cradle of the anti-regime uprising.

Most of the 30 civilian deaths were the result of raids carried out by security agents in the Damascus region, it said.

The United Nations says more than 7,500 people have been killed since March last year in a crackdown by Syrian forces on pro-democracy demonstrations.