AFP/Punjab

A 21-year-old woman was raped and hanged from a tree in Pakistan, police said, in a case bearing a chilling resemblance to a spate of recent sex crimes that sparked outrage in neighbouring India.

The woman's boyfriend of six months, named by police as Muhammad Saqib, was taken into custody after he confessed to the rape and murder.

Saqib admitted he tried to force the woman -- the daughter of blind parents -- to have sex with two of his friends, according to police. When she refused, investigators said the pair argued.

The woman, whom he allegedly had promised to marry, was found hanging from a tree the next morning.

Police are still looking for the two alleged accomplices.

"The incident occurred in Layyah district (in Punjab province) on Thursday night and was reported to the police on Friday when the local people saw a woman hanging from a tree," senior police official Ghazi Salahudin told AFP.

He said the woman was raped and strangled to death, and then her body was hanged to make it look like a suicide.

"But the branch was so low and the dead body was touching the ground in sitting position," he said.

The woman was the eldest of eight siblings and made a living by farming a small piece of land.

The incident has disturbing similarities to an attack in India last month, in which two teenage girls were found gang-raped and hanged from a mango tree in northern Uttar Pradesh state.

That attack sparked protests over police apathy, and was the latest to highlight India's dismal record on preventing sexual violence. Similar headline-making cases since then have piled pressure on the authorities there.

Pakistani police said Saqib had met the woman after he visited her house in his role as an assistant at a vegetable wholesale shop. They allegedly had been in a relationship for about six months.

A day before the murder, police said, Saqib had brought the woman for a date in the shop where he worked. He took her to the roof, where two of his friends were waiting.

When Saqib tried to persuade the woman to have sex with all three of them, she resisted, according to police.

She was then allegedly raped and killed. Police said Saqib had confessed to the attack, adding that they were still investigating if the woman had been raped by the other men as well.

Though the issues of rape, sexual assault and domestic violence are not as high-profile in Pakistan as they have been in India in recent years, they are widespread in the deeply conservative country.

In March, a 17-year-old Pakistani victim of a gang-rape died after self-immolating in protest at a police decision to turn a key suspect free.