"The situation is critical in the village of Karabila. Hundreds of injured people are inside the town requiring urgent medical treatment but have been prohibited to leave the village by US forces and we are not authorised to enter there," Dr Hamed al-Alousi, director at the nearby al-Qaim general hospital, said.

'Operation Spear', launched on 17 June, is the second Coalition offensive in the Anbar governorate designed to root out insurgents and prevent foreign rebels using the region as a staging post en route from Syria.

Karabila is close to the Syrian border and home to some 60,000 people. Al-Qaim, recently the scene of similar battles, is the nearest town to the village, some 320 km west of the capital, Baghdad.

According to al-Alousi, since Friday they received 15 bodies and treated 27 injured people in al-Qaim before US forces closed entry points to Karabila. He added that more than 100 people may have been trapped under houses destroyed during the offensive.

A US military source in Baghdad said that more than 90 insurgents had already been killed in the offensive but denied that there were civilian casualties.

"We have some medicine and emergency supplies in our hospital but as we cannot enter the village it has become useless," al-Alousi added.

Iraqi Red Crescent Society (IRCS) staff said that hundreds of residents had fled Karabila over the weekend carrying white flags and were camped in the desert a few kilometres away.

"We have reported that more than 7,000 families from Karabila are camped in the desert near to the village. All of them need urgent food and medical supplies and more than 150 houses have been totally destroyed inside the village," Firdous al-Abadi, a spokeswoman for the IRCS, said.

She added that thousands of families inside the village had run out of water, power and food supplies as they could not leave their homes and aid agencies have not been able to enter.

"The situation is very critical in the area and could become a humanitarian disaster. We are going to send a convoy with supplies on Tuesday and will try and get inside the village," a senior IRCS official said.

The convoy of four trucks and two ambulances will carry food parcels, blankets, tents and water canisters. The agency has asked for help from other aid organisations for medical supplies in particular.