A suicide bomber has attacked a joint Afghan-NATO patrol in eastern Afghanistan, killing at least 20 people.

NATO says the deaths Monday include three coalition service members and their interpreter.  U.S. officials identified the three NATO soldiers as American.  Afghan officials say the blast also killed six Afghan police officers, including members of a quick reaction force.

The Taliban claimed responsibility for the attack.

Local officials say the bomber attacked the coalition and Afghan patrol as troops walked near a market in the city of Khost.