The agreement meant that Nato troops and Taliban fighters were not supposed to come within 5km of the town centre, but last Thursday a group of 200 Taliban disarmed the local police force, destroyed the district centre and temporarily held local elders hostage.

Nato air strike

The Taliban made their move after accusing Nato of violating the deal during an air strike that killed the brother of Mullah Ghafour, a local Taliban leader. Nato commanders and tribal elders have said that the attack was outside the area covered by the truce.

Ghafour himself was killed in an air strike on Sunday.   

Colonel Tom Collins, a spokesman for Nato's International Security Assistance Force (Isaf), told the Associated Press news agency that troops were ready to help the government take control of the town, but that there "is no need to rush to action here".

"We are confident that the government of Afghanistan, with Isaf's support, will take back Musa Qala at a time and place that is most advantageous," he said.

A large number of Taliban fighters have reinforced the town with heavy weapons, a resident told Reuters by telephone on Wednesday, and Nato aircraft could be heard overhead.

Civilians fear that Nato will launch bombing raids in an attempt to force the Taliban out.

Al-Qaeda suspects arrested

Separately, US-led forces said they arrested two suspected al-Qaeda members on Wednesday in eastern Afghanistan, near the border with Pakistan.
   
Both were Afghans, the force said in a statement, but it did not identify them.
   
"The operation was conducted based on information provided about an al-Qaeda member known to pass correspondence for al-Qaeda senior leaders," the statement said.

Also on Wednesday, a roadside bomb killed two Afghan guards working for a US security company in the southern province of Kandahar, provincial officials said. Six guards were wounded.