Police say a bomb targeting a police chief's vehicle in southwestern Pakistan has killed one person and injured six others. Officer Mohammed Zaman says Quetta Police Chief Shahid Nizam Durrani was not harmed in Tuesday's attack. Zaman says the blast in Quetta was caused by a bomb planted on a motorcycle that was timed to explode when Durrani's vehicle passed by. Quetta is the capital of southwestern Balochistan province. Zaman said one passer-by was killed and three others were wounded. Three police officers who were in the vehicle were also wounded. Baloch nationalists have been waging a violent campaign against the government for years to demand greater income from gas and minerals extracted from the province.