Execution of Mumtaz Qadri, who killed Punjab governor Salman Taseer in 2011, prompts muted celebration and protests.
The execution of a man who killed the head of government of Punjab province over his call to reform strict blasphemy laws has revived the question of capital punishment in Pakistan.
Mumtaz Qadri was a bodyguard for Salman Taseer when he shot the Punjab governor dead in Islamabad in 2011.
After his arrest, he told police he had assassinated Taseer because he championed the cause of a Christian woman sentenced to death in a blasphemy case that arose out of a personal dispute.
Taseer had said the law was being misused and should be reformed.
Considering him a hero for defending Islam, Qadri's supporters took to the streets of Islamabad, Lahore, Peshawar, Quetta and Karachi following his hanging early on Monday morning.
While there were protests in big numbers - and equal amount of muted celebration - the hanging prompted outcry from various quarters that called for a moratorium on executions "as a first step towards abolition of the death penalty".
Champa Patel, director of Amnesty International's South Asia Regional Office, said: "Taseer was a brave voice for religious tolerance in Pakistan and his murderer should be brought to justice, but carrying out more killings is a deplorable way to honour Taseer's life and message.
"The death penalty is always a human rights violation, regardless of the circumstances or nature of the crime.
"While it is positive that the government is committed to tackling religious extremism and is taking proactive steps to ensure perpetrators of violence are brought to justice, carrying out yet more killings only continues the cycle of violence."
Earlier, Qadri 's attorney said his client told him he had no regrets for killing Taseer.
"I have met him twice in jail. He said that even if God gave me 50 million lives, I would still sacrifice all of them," lawyer Ghulam Mustafa Chaudhry said.
Protesters briefly blocked the main road between Rawalpindi and Islamabad on Monday after news of the hanging broke.
Police later dispersed them and closed off the road to prevent more demonstrations.
Chaudhry predicted larger demonstrations as a nationwide strike on Tuesday has been called by Qadri's supporters to protest against the hanging.
Late in 2011, an anti-terrorism court handed down a double death sentence to Qadri for murder and terrorism. The sentence was appealed and upheld by the Supreme Court late last year.
Jibran Nasir, a Pakistan lawyer and activist, says the country needs to unite on the issue of blasphemy laws instead of it becoming a war between Qadri's fans and Taseer's fans.
"I won't call anybody's death good news but the hanging has made a claim that when the state is challenged, it would enforce its laws," Nasir said from Karachi.
"Qadri's was a terrorist act and the Supreme Court upheld that. But when we see people celebrating or protesting, those are fringe elements. We're not talking about the liberals, moderates or even progressives here.
"What we need to remember is that Qadri was made this glorified poster boy of this huge problem. He was just the trigger, a foot soldier and the ones he was influenced by and looked up to are still roaming around freely."
National media played down news of the execution and the protests on orders of the government, two senior TV news anchors told AFP news agency.
There was no coverage of crowds of angry Qadri supporters who flocked to pay their respects at his family's house in Rawalpindi where his body was laid out on a bed, his head surrounded by roses.
The funeral is expected to be held on Tuesday.
"I have no regrets," Qadri's brother Malik Abid told AFP, tears rolling down his cheeks, while women chanted nearby.
He said the family had been called to the prison on Sunday evening by officials who said Qadri was unwell.
But when they arrived, Qadri greeted them with the news that authorities had deceived them and that his execution was imminent.
"I am proud of the martyrdom of my son," Qadri's father Bashir Awan told AFP, adding he was ready to sacrifice all five of his other sons "for the honour of the prophet".
Nasir, the lawyer, cautioned against making Qadri a hero in death, saying that by the show of affection on the streets, the common man is likely to be impressed by his actions.
"Qadri was showered with petals, sent cards on Valentine's Day, called a warrior before his death and a martyr after his hanging," he said.
"We should not make him a celebratory and not give him unnecessary coverage."
More than 100 people are charged with blasphemy each year in predominantly Muslim Pakistan, many of them Christians and other minorities.
Conviction of blasphemy carries a death sentence. No one has yet been hanged, but those convicted languish in prison.