DAMASCUS: Syrian regime forces shelled the northwestern town of Al-Haffe for an eighth day on Tuesday, sparking fears of an impending massacre and UN demands that its observers be granted access to the flashpoint.

Rami Abdel Rahman of the Syrian Observatory for Human Rights told AFP that regime forces were using heavy artillery against the town while massing reinforcements in preparation for a ground assault.

Residents told AFP that helicopter gunships were strafing rebel positions in Al-Haffe and said they feared a massacre if troops managed to enter the town, considered strategic because of its proximity to Qardaha, President Bashar al-Assad's home town.

Abdel Rahman said hundreds of rebel Free Syrian Army fighters are active in and around Al-Haffe, a town of about 30,000 people in Latakia province, setting the scene for a violent confrontation.

The UN Supervision Mission in Syria (UNSMIS) said it had received reports of “a large number of civilians, including women and children trapped inside the town and are trying to mediate their evacuation.”UN chief Ban Ki-moon joined UN-Arab League peace envoy Kofi Annan in demanding that unarmed military observers from UNSMIS be allowed into Al-Haffe.

One Syrian activist broke down in tears as she told AFP via Skype that army tanks were parked on the edge of Al-Haffe.

“They have never come this close before,” Sem Nassar said, adding: “There's only one doctor working to treat the wounded in the town,” and that most residents had fled.

Washington voiced concerns that President Bashar al-Assad's regime is planning to carry out new atrocities, after the massacre of 55 people last week in Al-Kubeir and at least 108 near Houla on May 25-26.

“The United States joins joint special envoy Kofi Annan in expressing deep alarm by reports from inside Syria that the regime may be organising another massacre,” US State Department spokeswoman Victoria Nuland said in Washington.

The Britain-based Observatory said troops also pounded a neighbourhood of the eastern city of Deir Ezzor with mortar fire on Tuesday, killing 10 civilians including a young girl, while five other civilians were killed in attacks on the central city of Homs.

“The situation is horrific, murderous,” an activist in Homs who identified himself as Abu Bilal told AFP via Skype.

Abu Bilal said 400 civilians — including women and children — were trapped in a school in the Jourat al-Shiah neighbourhood.