“The army is trying to go in with infantry from the direction of Al-Bassel football field and fierce confrontations with automatic rifles and heavy machine guns are taking place there,” activist Mohammad Al-Homsi told Reuters from Homs.

He said the military had shelled Baba Amro heavily on Tuesday and overnight before the ground attack started.

Another opposition source said hundreds of Free Syrian Army rebels were holding out in the area, situated between Baba Amro and Al-Inshaat district, which is also under army siege.

Several Western journalists are trapped in the battered district, although Syrian activists escorted British photographer Paul Conroy to safety in nearby Lebanon on Tuesday in a messy escape in which some of his rescuers were killed.

Reports from Baba Amro could not immediately be verified due to tight government restrictions on media in Syria, where President Bashar Assad is struggling to repress an almost year-long uprising against his 11-year rule.

A spokesman for the International Committee of the Red Cross, Hicham Hassan, could not confirm the assault but said the violence was making the humanitarian situation more difficult.

“This makes it even more important for us to repeat our call for a halt in the fighting,” he told Reuters in Geneva.

“It is essential that people who are in need of evacuation — wounded people, women and children — that we are able to offer them that with the Syrian Arab Red Crescent.”

Food supplies had been delivered to Homs and Idlib on Tuesday but it was hard to distribute aid due to the conditions on the ground, he said.

Activists say hundreds of civilians have been killed in besieged opposition districts of Homs, including at least 20 on Tuesday. Shells and rockets have been crashing into Baba Amro since Feb. 4. Army snipers pick off civilians who venture out.

Syrian troops bombarded the besieged town of Rastan, 20 km north of Homs, and several people were killed when a shell hit a house, the Syrian Observatory for Human Rights said.

Activists said troops and pro-Assad militiamen had also attacked the town of Helfaya, an opposition stronghold near the city of Hama, detaining people and raiding and burning houses.

YouTube footage posted by activists showed crowds of people in the nearby town of Kernaz in solidarity with Helfaya. Demonstrators danced, waved pre-Baathist era Syrian flags and chanted: “God support your oppressed subjects.”

Troops and militiamen launched a security sweep in the eastern Damascus suburb of Harasta, where telephone services have been cut off for the past month, activists said.

The United Nations says Assad’s security forces have killed more than 7,500 civilians since the revolt began last March.

“There are credible reports that the death toll now often exceeds 100 civilians a day, including many women and children,” UN Under-Secretary-General for political affairs Lynn Pascoe told the UN Security Council on Tuesday. “The total killed so far is certainly well over 7,500 people.”

Syria’s government said in December that “armed terrorists” had killed over 2,000 soldiers and police during the unrest.

As world dismay grew over the bloodshed, France said the Security Council was working on a new Syria resolution and urged Russia and China not to veto it, as they have previous drafts.

An outline drafted by Washington focused on humanitarian problems to try to win Chinese and Russian support and isolate Assad, Western envoys said. But they said the draft would also suggest Assad was to blame for the crisis, a stance his longtime ally Russia in particular has opposed.

International efforts to halt the violence in Syria have not been helped by disunity among Assad’s opponents. The Kuwaiti Parliament extended its own recognition on Tuesday to the exile Syrian National Council as “the representative of the Syrian people,” but other groups challenge the SNC’s legitimacy.

Meanwhile Kofi Annan, the newly appointed United Nations-Arab League envoy for Syria,  was expected to discuss the situation with UN Secretary-General Ban Ki-moon and member states in New York. He will then go to Cairo for talks with Arab League head Nabil Elaraby.