A Pakistani prison official says authorities have hanged nine convicts, including four brothers, the latest in a series of death sentences to be carried out since the country lifted a moratorium last year.

Tuesday's executions bring the nationwide total to 255 since December, when Pakistan lifted the moratorium on the death penalty following a Taliban attack on a school that killed 150 people, mostly children.

Pakistan has presented the reinstatement of capital punishment as a response to years of militant violence, but human rights groups say the majority of those executed were convicted of criminal offenses.

Prison official Khurram Ijaj says those executed Tuesday include four brothers convicted of murder. None of the nine were convicted of terrorism-related offenses.