Islamabad: At least seven people were killed in a bomb blast on Sunday at a camp housing families displaced from the North Waziristan tribal area amid the ongoing military operation there against terrorists, officials said.

A dozen people were also injured in the explosion at the camp located in the Hangu district of Khyber Pakthtunkhwa.

Police had no immediate clues about who was behind the blast or the motive behind it.

About a million people were evacuated from North Waziristan before the military launched its operation against terrorists in mid-June.

They have been sheltered at camps and many live with relatives, awaiting the end of the operation and their return to their native land as pledged by the government.

Prime Minister Nawaz Sharif strongly condemned the blast in Hangu, the state-run Radio Pakistan said.

In a message, Sharif extended his condolences to the families of those who lost their lives in the attack.

Hangu, which has a history of violence linked to sectarian groups and Taliban insurgents, is in the vicinity of the seven Federally Administered Tribal Areas including North Waziristan.