A Pakistani policeman used an axe to kill a man arrested for allegedly committing blasphemy, officials said on Thursday, days after an enraged mob murdered a Christian couple accused of the same crime.Tufail Haider, a 50-year-old from the minority Shiite sect of Islam, was arrested for allegedly making derogatory remarks toward the companions of the Prophet Mohammed and brought to the Civil Lines police station in the eastern city of Gujrat on Wednesday."Tufail was kept in the lock-up but he continued uttering derogatory remarks and hurled abuse at policemen. He looked like a malang (wandering preacher) and seemed mentally imbalanced," duty officer Ali Raza told AFP."Assistant Sub-Inspector Faraz Naveed, 36, became very angry on hearing the derogatory remarks against the companions of the Prophet and he killed the detainee with an axe in the lock up," he added.Naveed has been arrested and legal proceedings have been started against him, he added.Around 1,000 Shiites have been killed in the past two years in Pakistan, a heavy toll on the community that makes up roughly 20 percent of the country's 180 million-strong population, most of whom are Muslim.The historical split between Sunnis and Shiites originated over who among Mohammed's companions should succeed him as ruler of the growing Muslim empire following his death.There has been a recent surge in extra-judicial killings linked to Pakistan's blasphemy laws, which were put in place during the period of British rule and strengthened by former military ruler General Zia-ul-Haq in the 1980s.A Christian bonded labourer and his pregnant wife were killed Tuesday for alleged desecrating pages of the Koran in the eastern village of Chak 59, sparking condemnation from Prime Minister Nawaz Sharif.A Christian woman who has been on death row since November 2010 after she was found guilty of making derogatory remarks about Mohammed during an argument with a Muslim woman lost an appeal last month.

The latest incident also has shades of the shooting in September of an elderly British man with severe mental illness, who was sentenced to death for blasphemy in January.An internal investigation has found that the guard had been radicalised and goaded into the shooting by Mumtaz Qadri, a police bodyguard who murdered the Punjab governor in 2011 for suggesting reform of the blasphemy laws.