Imtiaz Ahmad, chief warden of the district prison, was targeted late Saturday when two people riding a motorcycle sprayed him with bullets near his office, police said.
"Two armed persons riding a motorcycle opened fire on Imtiaz Ahmad and fled. He received critical wounds and died instantly," Qazi Abdul Wahid, a senior police official in Quetta, told AFP.
Police and security forces are frequently attacked in the insurgency-plagued Baluchistan province, of which Quetta is the capital.
Al-Qaeda-linked militant group Lashkar-e-Jhangvi (LJ) claimed responsibility for Saturday`s killing, telling local media: "The slain warden was a cruel person and used to subject our imprisoned leaders and workers to torture."
LJ has orchestrated violent attacks on Muslim minority Shiites, and other police officials in Baluchistan say they have been threatened by the group.
Earlier this month a senior police official was assassinated in Quetta in another drive-by shooting claimed by LJ.
On April 29, British aid worker Khalil Dale was found beheaded in Quetta, nearly four months after he was kidnapped in the city. There has been no claim of responsibility for his murder.
Hundreds of people have been killed since separatist Baluch rebels rose up in 2004, demanding political autonomy and a greater share of profits from oil, gas and mineral resources in the region. (*)
Editor: Kunto Wibisono
Copyright © ANTARA 2012
