Pakistani officials say more than 100 people have been detained after a mob beat a Sri Lankan factory manager accused of blasphemy and set his body ablaze.
The December 3 attack has triggered widespread condemnation among Pakistan's political and military leadership, religious figures, and members of civil society.
"The horrific vigilante attack...is a day of shame for Pakistan,” Prime Minister Imran Khan tweeted, vowing to that all those responsible will be punished "with full severity of the law."
Blasphemy is an explosive issue in the Muslim-majority country, where even unproven allegations can stir up violence and large protests.
Hassan Khawar, a spokesman for the Punjab provincial government, said on December 4 that 118 suspects had been detained in ongoing raids over the incident in Sialkot, a district in the central province about 200 kilometers from Islamabad.
Workers at a garment factory grabbed Priyantha Kumara, an export manager, tortured him to death, and publicly burned the body, according to police.
A local resident has told RFE/RL that the factory workers claimed that pages of Koran were found in the victim's office dustbin.
Kumara was described as a Christian who had been working at Rajko Industries for 10 years.
Gruesome video clips shared on social media showed a crowd of men beating a body with sticks while chanting slogans against blasphemy.
Other videos showed a body set ablaze and people taking selfies with it.
Investigators were using footage from CCTV cameras and mobile-phone data in their investigation, Khawar said.
Sri Lankan Prime Minister Mahinda Rajapaksa said he was shocked by the brutal attack, adding, "SriLanka and her people are confident that [the Pakistani prime minister] will keep to his commitment to bring all those involved to justice."
Blasphemy is a hugely sensitive issue in Pakistan, where unproven allegations can lead to those accused being gunned down, burned alive, or bludgeoned to death.
The incident in Punjab Province occurred less than a week after hundreds of angry protesters ransacked and burned a police station and several checkpoints in northwestern Pakistan, demanding that officers hand over a man who had allegedly burned a Koran.
In April 2017, a mob of students and officials lynched a journalism student on false blasphemy charges at a Pakistani university.
Critics say Pakistan's blasphemy laws are unevenly applied and frequently abused to settle personal disputes.