Police in southwestern Pakistan say a bomb has hit a vehicle in Baluchistan province, killing three workers from a state-owned oil and gas company.

Authorities said the blast Thursday in the town of Jaaferabad also wounded at least four other people.

No group immediately claimed responsibility for the attack.

Baluchistan has faced an Islamist militancy, a local insurgency, and sectarian violence between majority Sunnis and minority Shi'ite Muslims.