The manager of a Sri Lankan factory in Pakistan was beaten to death and set on fire Friday by a group of people, police confirmed, in an incident that local media reported was linked to blasphemy.

Blasphemy is causing outrage in Pakistani streets, and even the slightest hint of insult to Islam may inflame protests and incite extrajudicial executions.

Prime Minister Imran Khan said he would personally oversee the investigation into this "horrific attack," which he also called a "day of shame for Pakistan."

"No one should be mistaken in thinking that all those responsible (for the accident) will be severely punished by law," he wrote on Twitter.

Rights groups say similar accusations are often leveled out of revenge, with minorities particularly targeted.

Police told AFP that Friday's accident occurred in Sialkot, 200 kilometers southeast of the capital, Islamabad.

Horrific videos circulated on social media showed a crowd beating the victim, chanting slogans against blasphemy, while other videos showed fire burning in his body.

Many of the attackers did not try to hide their identity, and some took selfies in front of the burned body.

Punjab Chief Minister Usman Buzdar wrote on Twitter, "I am shocked by the horrific Sialkot incident. No one is allowed to take justice into their own hands. Rest assured, individuals involved in this inhuman act will not be extradited!!"

Punjab police said they would investigate "all aspects" of the incident.

Hassan Khawar, a spokesman for the Punjab government, told reporters in Lahore that "the police arrested 50 people after the incident."

"The CCTV footage is being carefully reviewed and we have been directed to complete the investigation within 48 hours," he added.

"We are very clear that Islam teaches us peace and tranquility and hatred of violence," he added.

Meanwhile, the representative of the Prime Minister, Taher Ashrafi, said that "those involved in this barbaric act misused the blasphemy law and tarnished the reputation of Islam."

The slogans heard in the videos were the same as those used by supporters of the "Labaik Pakistan" movement, an anti-blasphemy party.

Labeik Pakistan has in the past paralyzed the country with protests including an anti-French campaign following last year's republishing of cartoons of the Prophet Muhammad by Paris-based magazine Charlie Hebdo.