At least seven police were killed and 22 injured in a bomb attack and a subsequent ambush in southwestern Balochistan province early Wednesday, police and local media reported.
The blast targeted a truck carrying the officers on the outskirts of Quetta, the capital of Balochistan, provincial home minister Mir Sarfraz Bugti told reporters.
He said it was premature to say if it was a blast triggered by remote control or a suicide bombing.
Local media, however, quoting unnamed police officials, reported the blast could be the act of a suicide bomber.
Footage aired on local Geo TV showed charred wreckage of the truck lying in the middle of the road, while honking ambulances shifted the dead and injured to hospital.
Waseem Baig, a spokesman for the Civil Hospital Quetta told reporters that at least 10 injured -- several critically -- were admitted.
One hour after the bomb blast, another police officer was killed in an ambush by unknown gunmen in a busy locality of Quetta.
A Tehrik-e-Taliban Pakistan (TTP) statement later claimed responsibility for the Quetta blast, claiming one of its suicide bombers targeted the police in retaliation for alleged extra-judicial killings of its members in custody.
The large Balochistan province, which is also considered to cover parts of neighboring Iran and Afghanistan, is strategically important because of the rich presence of copper, zinc and natural gas.
It has been beset by violence for over six decades, with separatists claiming it was forcibly incorporated into Pakistan upon the end of the British rule in 1947.
Various sectarian outfits, including Lashkar-e-Jhangvi, have also been active in the region, especially in Quetta, for the last decade.