Police questioned dozens of people for clues about assailants who shot dead a senior government official in southwestern Pakistan, an attack a rebel group has claimed responsibility for, an official said Sunday. Attackers armed with assault rifles sprayed the four-wheel-drive vehicle of Raziq Bugti, an adviser and spokesman for the government of southwestern Baluchistan, as it drove through the province's capital of Quetta on Friday. The government blamed the nationalist rebel group the Baluch Liberation Army for the attack, and a purported spokesman for the group claimed responsibility. Since the attack, police have carried out raids in various parts of Quetta, and had detained 83 people by late Saturday, said Rehmatullah Khan Niazi, a senior Quetta police investigator.