A mentally unstable homeless man was beaten to death before his body was set on fire for allegedly burning pages from the Quran in central Pakistan, police said.
A 2,000-person group snatched the man from a police station in a village on the outskirts of the city of Bahawalpur, 100km south of Multan, after officials refused to hand him over on Tuesday.
Ghulam Mohiuddin, a local police chief, said Ghulam Abbas, in his early forties, was taken into custody after people said they caught him burning pages of the Muslim holy book.
"After some time, more than 2,000 people surrounded the police station and asked the police to hand over the man to them, and upon refusal they ransacked the police station and took the accused with them," Mohiuddin told the AFP news agency.
"The protesters also set fire to several motorcycles and vehicles parked in the police station and damaged the quarters of police officials. Later they took away Ghulam Abbas to a main crossing, beat him to death and set his body on fire."
He said the man was mentally unstable and "was not aware of even the location of his residence".
Ahmed Ishaq Jahangir, district police chief, told the AFP news agency that the mob was too much for the police to handle after some in the group incited others to take action.
The independent Human Rights Commission of Pakistan (HRCP) has demanded an inquiry into the killing.
"HRCP... strongly condemns not only the burning to death of a man in Bahawalpur, who had been accused of desecrating pages of the Koran, but also the authorities' failure to prevent a horrendous crime that was not at all unexpected," the group said.
Amnesty International has also condemned the killing, saying the failure of authorities in the Punjab to bring the perpetrators to justice will send a message that "anyone can commit outrageous abuses and attempt to excuse them as defence of religious sentiments".
Pakistan's anti-blasphemy laws make defaming Islam or the Prophet Mohammed, or desecrating the Quran, punishable by death.
The London-based rights group also called for the reformation of the laws, which they said were vaguely formulated and have led to vigilantism, particularly in the Punjab.
The laws must be reformed "to ensure they cannot be used maliciously to settle disputes or enable private citizens to take matters into their own hands," an Amnesty statement issued on Thursday read.
Former Punjab governor Salman Taseer was shot dead in January last year by one of his police bodyguards for opposing the tough laws.
In June another mob attacked a police station north of Quetta demanding a man detained for allegedly burning a Quran, with the incident leaving one protester dead and 19 wounded.