A suspected suicide bomber has struck close to the entrance to the US embassy in Kabul, Afghanistan, witnesses and police say.

At least one person, reportedly a civilian, was killed, although one police official said more had died. Reports said the bomber detonated explosives about 200m from the heavily guarded entrance to the US compound. Security in Afghanistan has become a key concern as the country faces an increasingly strong Taleban insurgency. Kabul's police chief, Mohammad Ayoub Salangi, said one person had been killed and six injured.

However, the city's head of criminal investigations told reporters that four had died in the bombing. The Associated Press said the US embassy was hosting a Thanksgiving Day event, and Americans and others foreigners were entering the compound at the time of the explosion.