The deaths come hours after Afghanistan's interior ministry said that civilian deaths were on the rise in the country.

New figures showed that there were 173 civilian deaths between March 21 and April 21, a 33 per cent increase on the same period in 2009.

The statistics did not record who was responisble for the deaths but the UN has said that it is the Taliban which are responsible for most civilian deaths in Afghanistan.

Deaths caused by international troops in Afghanistan have caused widespread anger in the country. The US revised its rules on using air attacks and other weaponry last year after facing criticism for accidently killing civilians during operations against the Taliban.

Last week, the French military admitted responsibility for the deaths of four civilians who were killed during a clash with Taliban fighters on April 6.

The attack was followed by a controversial incident on April 20 in which Nato troops fired on a vehicle that approached their convoy, killing four civilians.

A recent US report confirmed the spike in civilian deaths in recent months.

"Preventing Afghan casualties remains our goal despite recent setbacks," Lieutenant-Colonel Todd Vician, a Nato spokesman based in Kabul, said.