Kabul bomb attack near US embassy

At least four civilians have been killed in a suicide bomb attack near the American embassy in the Afghan capital Kabul, officials say.

About 20 others were injured when a man driving a car blew himself up.

A spokesman for the embassy, which was closed for a Thanksgiving Day event, said none of its staff had been killed or injured.

Violence across Afghanistan has soared to levels not seen since the Taleban were driven from power in 2001.

The embassy is close to government buildings and one of the city's major landmarks, Massoud Circle.

The attack took place early in the morning, when many people were out on the streets heading to work.

It is a public holiday at the US embassy, although Thanksgiving Day celebrations were due to be held later on Thursday.

The BBC's Sanjoy Majumder in Kabul says all roads leading to the blast site were cordoned off, leading to massive traffic jams.

Ambulances ferried the wounded to hospital while police and security teams sifted through the blast wreckage looking for evidence.