A Taliban suicide bomber rammed a van into an armoured Nato bus today in Kabul, killing 13 American troops and four Afghans, US and Afghan officials said, in the deadliest attack on coalition forces in more than two months.

There are reports that anti-aircraft fire has been heard for the fourth straight night in the Afghan capital of Kabul.

It was coming up on 9 pm, a clear night in Kabul, and few Afghans were on the streets of their capital. Curfew was beginning in a half hour, and the Taliban militia who run the capital don’t take curfew-breaking lightly.