Islamabad - Qadri, a former police bodyguard, shot liberal Punjab governor Salman Taseer 28 times in an upscale market in Islamabad in 2011.
Pakistan on Monday hanged the assassin of a governor seeking reform of the country's blasphemy law, officials said, in a blow to the supporters who feted Mumtaz Qadri as a hero and had threatened violence if he was executed.
Officials stepped up security in the garrison city of Rawalpindi as hundreds of people began gathering at Qadri's family home early Monday, and some roads were closed in the nearby capital Islamabad as authorities braced for protests from hardliners.
Qadri, a former police bodyguard, shot liberal Punjab governor Salman Taseer 28 times in an upscale market in Islamabad in 2011.
He later admitted the killing, saying he objected to the politician's calls to reform controversial blasphemy laws - a hugely sensitive issue in Pakistan.
"Qadri was hanged in Adiala jail early Monday morning" in Rawalpindi, senior local police official Sajjid Gondal told AFP.
Qadri's body was being displayed to supporters at his family's home in the city, where Rangers and police in riot gear as well as ambulances and dozens of police vehicles were stationed, an AFP reporter there said.
Armed Rangers could also be seen on the roof of the building housing Qadri's residence, while authorities blocked some roads in the neighbourhood.
Cries were heard from inside the house as hundreds of men and women gathered, and mosques could be heard broadcasting news of the execution.
"I have no regrets," Qadri's brother Malik Abid told AFP, tears rolling down his cheeks, while women chanted poetry nearby.
He said the family had been called to the prison Sunday evening by officials who said Qadri was unwell.
But when they arrived, he greeted them with the news that authorities had deceived them, and that his execution was imminent.
"We started crying, but he hugged us and chanted 'God is great,'" Abid said.
"We have beefed up security in Rawalpindi to maintain law and order and to deal with any untoward situation," Gondal said.
In the port mega-city of Karachi, some petrol stations were closed after Qadri supporters ordered them shut.
Qadri lost a petition for the Supreme Court to review his sentence in December last year.
The decision came after the court warned in October that in Islam a false accusation can be as serious as the blasphemy itself, and that calls for blasphemy law reform "ought not to be mistaken as a call for doing away with that law".
The court's decision to uphold the sentence sparked rallies in which supporters said that if Qadri was executed those responsible should also be put to death.