A car bomb explodes outside a compound housing Westerners in Kabul hours after US President Barack Obama visits the Afghan capital.

Senior Taliban leaders tell Channel 4 News that talks with the United States have started again in Qatar - intransigence on all sides is blamed for the failure of talks earlier this year.

Two British service personnel are shot dead by an Afghan man wearing military uniform, bringing the number of NATO troops shot by Afghan forces to 16 this year alone.

The soldier accused of killing civilians in southern Afghanistan in a shooting rampage is to be charged with 17 counts of murder. But the Taliban have vowed to avenge the deaths.

A US soldier could plead insanity if he is charged with the murders of 16 Afghan villagers last weekend, his lawyer tells Channel 4 News.

With fears of reprisal attacks and a mass walk-out of Kabul's parliament, Channel 4 News examines what lies ahead for the US soldier accused of killing Afghan civilians - and for the whole mission.

As a US soldier is held in custody after shooting dead Afghan civilians, a spokesman for Nato-led forces tells Channel 4 News the attack is "simply not understandable" and a "step back".