The man, Mehram Ali, was hanged at a prison in Faisalabad early on Tuesday after appeals against his sentence were rejected.

Several people have been given death sentences for their involvement in sectarian violence in Pakistan, but this is the first case in which the authorities have actually proceeded with an execution.

BBC Correspondent Zaffar Abbas in Islamabad says that this decision indicates that the authorities now plan to deal with all such cases in the same strict manner.

Mehram Ali was arrested soon after the bomb had gone off inside the premises of the sessions court building in Lahore in January last year.

Among those who were killed in the explosion were a senior leader of the Sunni Muslim group, Zaiur Rehman Farooqui, several policemen and a journalist.

The bombing resulted in more sectarian violence in the province of Punjab.

Scores of people were killed in a series of organised armed attacks which the police believe were linked to conflict between the militant groups of the Shia and Sunni Muslims.

Mehram Ali's trial in front of an anti-terrorist court lasted several months.