A teenager walked into a Pakistani police station and shot dead a 65-year-old man accused of blasphemy, officials have said.

Officers arrested the assailant after the shooting in the town of Sharqpur, located in Punjab province, said Moazzam Ali, the police officer in charge of the station where the shooting happened.

The victim, named as Khalil Ahmad, was arrested four days ago under the country's strict blasphemy law, Ali told AFP news agency.

Ahmad was a member of the minority Ahmadi community, whose members profess to be Muslim. But Pakistan's penal code explicitly discriminates against them.

Ahmadis are prevented by law from "posing as Muslims", declaring their faith publicly, calling their places of worship mosques or performing the Muslim call to prayer. They were declared non-Muslim in 1974 for their belief in a prophet after Mohammed.

Retaliation suspected

Ahmad and three other Ahmadis had asked a shopkeeper in their village to remove inflammatory stickers denouncing their community, said Saleem ud Din, a spokesman for the Ahmadi community in Pakistan.

In retaliation, the shopkeeper filed blasphemy charges against the four men on May 12.

Ahmad, a father of four, was in police custody when the teenage boy walked in, asked to see him, and shot him dead, Din said. He added that police told him that the youth, a high school student, had been arrested.

Din said the blasphemy law was being used by people as a way to settle personal scores behind the smokescreen of religion.

Blasphemy is an extremely sensitive subject in Pakistan, where people convicted of the crime can receive a life sentence or the death penalty. However, crowds or individuals often carry out the punishment of suspects themselves.

This is the second murder involving the country's controversial blasphemy laws in less than a fortnight. On May 7, gunmen in the city of Multan killed a lawyer who was representing a university professor on trial for blasphemy.