Defections, aid convoys and a UN-led visit have not stopped the Assad regime from continuing its vicious crackdown in Homs.

While there was a brief lull in the hostilities during a visit by UN humanitarian chief Valerie Amos, shelling and shooting have resumed to the besieged city.

Amos said part of Homs had been destroyed after a month of shelling and by a military ground assault on the Baba Amr district.

But pleas for more concrete help from activists and residents still trapped in the city have fallen on deaf ears and anger is mounting about the West's seeming inaction.

The Syrian Red Crescent was finally allowed into Baba Amr after the opposition made a strategic retreat. By then, however, most of the residents had fled the neighbourhood.

Activists reported that at least another 20 people were killed on 9 March with no signs of the assault easing.

"The army is still here, still shooting, still shelling. At least 20 people died today," Sami Ibrahim, an activist working for the Syrian Human Rights Network, told International Business Times UK.

"The troops killed 10 people while they were making their way out of a mosque, where they had gone to pray," he said.

The humanitarian situation in Homs is become more critical with each passing day. As soon as aid convoys are allowed into one neighbourhood, the army moves into another district.

"The priority now is for the people who fled their homes to find shelter," Ibrahim said.

"We also need to make sure that women and children are protected from the army. A lot of women have been raped," he added.

Although the wounded need to be taken to hospital, the facilities are not there, so they do not have access to medical treatment, Ibrahim said. He made a desperate plea for medical equipment and qualified staff.

Even those who have escaped were reluctant to seek treatment elsewhere out of fear of being killed, arrested or tortured, according to Ibrahim.

"Private hospitals are scared to open their doors to us for fear of being targeted by the regime. This is why we have tried to set up field hospitals, but their capacity is limited."

UN-Arab League envoy Kofi Annan is due to arrive in Damascus but his call for dialogue with the regime has angered civilians and activists.

"What the regime is doing is just unacceptable. While activists keep uploading videos and images of the atrocities committed by the regime, we have received little humanitarian aid," Ibrahim said.

"Anger is mounting and we do not know how much more it will take before the world stops watching us die. We need a humanitarian response on the ground now."