The executions were carried out on the 17th anniversary of the tests, which made Pakistan the world's seventh nuclear-armed power -- a landmark event for the impoverished Muslim country of 200 million people.
The trio were sentenced to death for hijacking a Pakistan International Airlines aircraft with 30 passengers on board on 24th May 1998, four days before the country's first nuclear test.
There were 30 passengers on board and the hijackers wanted to take it to India, but pilot Captain Uzair Khan duped them by landing at the Hyderabad airport, as the hijackers were told that they had landed in India.
Later, the security forces stormed the plane and overpowered the hijackers.
Meanwhile, another death row prisoner was hanged in Karachi Central Jail. He was guilty of killing a minor boy in 2003.
The three plane hijackers were hanged among other 8 people who were convicted of various murder cases.
According to Amnesty International, Pakistan has executed 139 people since December 2014 - 132 were carried out this year
