A Pakistani poured kerosene over his sleeping wife and daughter and burned them to death in the country's latest example of so-called honour killings, police said today. The 45-year-old man, named as Jalil Ahmed, snapped after his brother caught his daughter having sex with a neighbour in the remote town of Samasatta, about 105 km south of the central city of Multan, police said.

He rushed back from his workplace in the southern city of Karachi and with the help of his brother tied the 20-year-old girl, named as Shomaila, and her mother to wooden beds as they slept, local police officer Arif Nawaz said.

They then set light to the two women - the girl for having an affair and the 40-year-old mother Azeem Mai for "not discouraging her daughter", the police officer said.

Police have arrested the girl's father and uncle and efforts were under way to arrest their neighbour, who fled the town after the incident.

"We have registered a case against three persons and arrested two of them, who have confessed the crime," the policeman said.

"They said they had killed them for honour."

Officials say about 4000 people, mostly women, have died as a result of brutal "honour punishments" in rural areas of Pakistan over the past four years.

Last week a Pakistani widow and her two daughters were beaten and forced to parade naked through a market after her son allegedly had an affair with another man's wife in Qabula, 175 kilometres east of Multan.

Mukhtaran Mai, 33, became the victim of a notorious gang rape in June 2002, in Meerwala village, which is in the same area. She was raped for more than an hour on the orders of a tribal council to atone for her brother's alleged affair with a woman of a powerful rival clan.

President Pervez Musharraf early this year signed into law a bill introducing the death penalty for honour killings.