The US and its allies are growing increasingly concerned as Afghanistan shows signs of unravelling in its first democratic transfer of power from President Hamid Karzai.

A plot to assassinate the former British ambassador to Afghanistan was foiled, the UK’s current representative in Kabul has said.

A massive three-day battle in southern Afghanistan between Nato and Taliban militants has killed more than 100 people, including insurgents, civilians and police, Afghan officials said today.