A suicide bomber killed at least 21 people, including three coalition soldiers, in an attack on a joint NATO and Afghan patrol in eastern Afghanistan.

Provincial police chief General Sardar Mohammad Zazai told VOA the attacker struck a checkpoint where coalition and Afghan forces were conducting biometric surveys of residents in Khost city. The blast took place near a busy market.

The U.S. Embassy in Kabul said three NATO service members and an Afghan interpreter were among those killed in the blast.

The coalition soldiers were said to be American. Afghan officials say police officers were also among the dead. More than 32 people, including women and children, were wounded in the attack.

There was no immediate claim of responsibility for the bombing. The al-Qaida and Taliban-linked Haqqani network is said to be active in Khost Province, which borders Pakistan's North Waziristan tribal region.

The militant group has been blamed for a number of deadly attacks against international forces in Afghanistan.

Elsewhere in the east, Afghan officials say at least six women and children were killed Tuesday when the tractor they were riding on struck a roadside bomb in Logar province.

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