The governor of a province in south-western Pakistan where 81 people died in a massive bombing says security officials are too scared of retribution from terrorists to do their jobs.

Governor Zulfiqar Magsi said Saturday's bombing in the city of Quetta was the result of a failure of the security and intelligence agencies in the province.

More than 160 other people were wounded when the blast ripped through a vegetable market where people were buying produce.

Most of the dead and wounded were Shiite Muslims.

The minority sect has often been targeted by Sunni extremists who view them as heretics and not real Muslims.

Human rights groups have accused the government of not doing enough to protect them.