ISLAMABAD, Pakistan — The prison authorities executed a Pakistani man on Wednesday who human rights groups say was tortured by the police into confessing to a murder while he was still a teenager. The execution, which took place despite pleas for mercy from rights activists and religious leaders, was the latest in a series in Pakistan that has prompted international condemnation.

Pakistan lifted a moratorium on the death penalty in December after at least 150 people, mostly children, were killed in an attack on an army school that jolted the country. Initially, officials said the executions would be limited to convicted terrorists, but within weeks, they began to include all manner of death row prisoners.

In the latest case, Aftab Bahadur, 37, was hanged in Kot Lakhpat Jail in the eastern city of Lahore on Wednesday morning. Mr. Bahadur had been convicted of killing a woman and her two children in 1992 during a robbery attempt. The execution of another man convicted in the case, Ghulam Mustafa, was canceled after he was pardoned by the victims’ family, officials said.

Mr. Bahadur was 15 years old when he was convicted, and the minimum age for the death penalty was raised to 18 in Pakistan only in 2000. This week, Reprieve, a group that campaigns against the death penalty, said that two witnesses in the case had recanted their statements and declared Mr. Bahadur innocent. A day before his execution, The Guardian newspaper in Britain published a letter by Mr. Bahadur in which he passionately defended himself. “I doubt there is anything more dreadful than being told that you are going to die, and then sitting in a prison cell just waiting for that moment,” he wrote.