A vehicle carrying Pakistani construction workers hit a roadside bomb in a remote area in southwestern Baluchistan province on Friday, killing five laborers and wounding two soldiers who were escorting them, a government official said. No one claimed responsibility for the attack, and Zahid Shah, a deputy commissioner in the district of Sibi where the bombing happened said they were still investigating. Troops often escort laborers in the volatile southwestern Pakistan for security reasons. Baluchistan has been the scene of a long-running insurgency by Baluch separatist groups such as the Baluchistan Liberation Front and the Baluchistan Liberation Army, which for decades have attacked government forces to press their demands for independence. The region also has militant groups that stage regular attacks.