A suicide bomber has attacked a NATO convoy in eastern Afghanistan, killing at least 12 people.

Provincial officials say the attacker was on a motorcycle when he struck the convoy Wednesday as it traveled through the city of Khost.

At least 16 others were wounded in the blast, and Afghan officials say the casualties include civilians, police officers and coalition troops.

There was no immediate claim of responsibility for the attack. 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, which is believed to be based in North Waziristan, has been blamed for a number of deadly attacks against international forces in Afghanistan.