Pakistan has hanged 12 convicts, the largest number of people executed on the same day since the country overturned a ban on executions.The men were terrorists, murderers or guilty of "heinous crimes", an interior ministry spokesman said. At least 27 convicts have been executed since the moratorium was lifted, most of them militants, Reuters reported.It is estimated there are more than 8,000 Pakistanis on death row. Rights groups say many convictions are unsafe.A moratorium on hangings was lifted for terror-related crimes after a Taliban attack in December killed more than 150 people, mostly children, at a school in Peshawar.But last week it became clear that officials had widened the capital punishment policy to include all prisoners on death row whose appeals had been rejected.The subsequent executions have taken place despite calls by the UN not to resume them. Human rights groups say that prisoners often do not receive a fair trial within Pakistan's outdated criminal justice system and that poorly-trained police often use torture to force confessions.