Pakistani security officials and witnesses told RFE/RL the bomb attack targeted a checkpoint of a locally recruited tribal force known as the Khasadar in the Shewa area of North Waziristan, about 20 kilometers east of the border with Afghanistan.

Members of the Khasadar force in the area told RFE/RL that the bomb had been planted at the checkpoint during the early morning hours when there were no security forces present.

They said the bomb was detonated at 8 a.m. when four members of the Khasadar force arrived for duty and entered the post.

There was no immediate claim of responsibility for the attack.

Pakistan’s Taliban, the Tehrik-e Taliban Pakistan (TTP), has previously claimed responsibility for similar attacks in North Waziristan.