A senior Afghan army commander and 12 other military officials have been killed after a helicopter crashed in western Afghanistan.

"General Fazel Ahmad Sayar, the army corps commander for the western region, and 12 other army personnel were martyred in the incident," the Afghan defence ministry said in Kabul on Thursday.

The helicopter was flying low due to bad weather when it hit a mountain in the Adraskan district of Herat province, the statement read.

The Taliban, who are fighting the government and foreign powers backing it, claimed they had shot it down.

General Mohammad Zahir Azimi, a defence ministry spokesman, denied the Taliban claim, saying there had been no "insurgent" activity in the area of the crash.

Investigation launched

The M-17 helicopter was on its way from the western province of Herat to the neighbouring province of Farah when it went down.

Sayar was one of the Afghan army's four regional commanders and was in charge of Afghanistan's western region.

A recovery team had been sent to locate the crash site and retrieve the bodies and an investigation had been launched, Abdul Rashid, the district chief of Adraskan, said.

Two British soldiers serving with Nato-led international troops were also killed in an explosion while fighting Taliban in southern Afghanistan, military officials said on Thursday.

The blast occurred northeast of Gereshk district in the southern province of Helmand, the British defence ministry said in a website statement.

The fatalities brought to 141 the total number of British deaths in Afghanistan since their deployment in late 2001.