The victim’s body was then set alight, according to witnesses.
According to a story by the BBC, the unnamed victim had earlier been handed over to the police after burnt pages of the Koran were found in a mosque in Dadu district, 330km (200 miles) north of Karachi, where he had been staying overnight.
Hours later a mob went to the police station, seized the man and killed him.
The district police chief, Usman Ghani, told the BBC the gruesome incident was filmed on cell phones. He said the video was being reviewed to help identify those responsible for the attack.
The BBC reported that 30 people have so far been detained in connection with the attack.
The local police chief and five of his officers have been arrested for failing to protect the man.
The BBC’s Karachi correspondent Shahzeb Jillani said blasphemy is a highly sensitive issue in Pakistan, where scores of people have been killed by mobs or vigilantes.
He added that the controversial laws are often misused to persecute minorities or settle disputes.
The BBC said the case was dismissed last month after a neighbor testified that she had been framed, possibly to force Christians out of her neighborhood outside Islamabad.
In 2011, two leading politicians – the Governor of Punjab province, Salman Taseer, and the Religious Minorities Minister, Shahbaz Bhatti – were assassinated after speaking out against the existing blasphemy legislation. ANS