Diplomacy fails as Assad's troops continue their slaughter in Syria

Dozens of civilians and rebels killed as forces loyal to hated President unleash fresh bombardment on Homs

The world appeared powerless to stop the bloodshed as the Syrian regime continued its bombardment of the central opposition stronghold of Homs yesterday, reportedly killing scores more people despite a massive international outcry.

Western and Arab nations scrambled to come up with another salvo of diplomatic pressure as the siege of the city about 100 miles north of the capital, Damascus, entered a sixth day. Activists and human rights groups described scenes of horror caused by relentless mortar and rocket attacks. In London, Prime Minister David Cameron accused President Bashar Al-Assad of being "hell-bent on killing, murdering and maiming [his] own citizens".

The international community has seen its diplomatic options shrink since China and Russia vetoed a watered-down United Nations Security Council resolution calling for a transition of power. Yesterday, a senior Arab League official said the bloc was considering recognising the opposition Syrian National Council as the legitimate representatives of the Syrian people and allowing them to open offices in Arab countries. Germany, meanwhile, expelled four Syrian diplomats in protest at the arrest of two men accused of spying on Syrian activists in the country, and Libya gave the Syrian envoy 72 hours to leave Tripoli.

Human rights groups outside the country reported that up to 70 people may have been killed in the onslaught on Homs yesterday, taking their count since the assault began late last Friday to well over 300 dead. Human Rights Watch said people were bleeding to death in the streets with residents afraid to brave the bombardment to save them. It said Assad forces had taken over Homs University's campus and blockaded areas of the city, preventing people from getting out, and food, medicine and other supplies from getting in.

Dr Ali al-Hanzoury, who was treating scores of injured civilians in a field hospital at Bab Amr yesterday, said the humanitarian situation in Homs was so bad that there was only one doctor per 100 patients. Dr Hanzoury said: "All we have for dressing wounds is cotton and plasters. There are so many injured people and they have all kinds of wounds. Lots of them have been buried under their homes following shell attacks."

He said many of his nurses and volunteers had been injured or killed. "We lost one of the medics on Sunday when the military shelled our field hospital. Both of his legs were blown off in the explosion. One of the volunteers, a local teacher, was decapitated after the shell exploded."

Syrian state TV repeated allegations that "foreign terrorists" were behind the violence. Accounts are difficult to verify as the government has so far denied media requests to travel to the stricken city. US officials were weighing up whether to try and send more international aid to Homs. They have so far avoided giving any direct assistance to the opposition, wary of getting too deeply involved in a conflict that some say could erupt into a full-blown sectarian civil war and is already estimated to have claimed 5,400 lives.

Speaking at conference in Sweden yesterday, Mr Cameron vowed to keep up pressure on the regime. "We need to take the toughest possible response we can," he said, adding he had been disappointed by the Russian and Chinese vetoes on Saturday, which analysts say have buoyed President Assad.

"It is clear the Syrian government has interpreted the Russia-China veto as a carte blanche to launch an all-out assault on cities like Homs without caring who's killed in the process," said Anna Neistat, of Human Rights Watch.

In Damascus, Mr Assad appeared immune to the desperate lobbying to stop the violence. More crowds of chanting regime loyalists marched through the streets yesterday hollering his praises. State television showed footage of citizens of some of the pro-Assad neighbourhoods of Homs walking round as if nothing was amiss. They also showed a cache of explosives they claimed to have found in the mountain town of Zabadani, about 20 miles northwest of the capital, which is also under siege by regime forces.

At the military hospital in Damascus, staff said they had buried 10 soldiers and two officers killed in Zabadani. With the area completely blocked off, there is no word of how many casualties the opposition rebels have suffered.