AMMAN (AFP) – Three Jordanian men were charged on Tuesday with premeditated murder after allegedly stabbing to death their divorced sister as well as burning her body and house over her "bad reputation," police said.

"The three brothers all under 30, agreed to kill their 40-year-old sister on Sunday because she allegedly had a bad reputation," in Abu Alanda, in southeast Amman, a police spokesman told AFP.

"She was stabbed 15 times. One of the three told police that the mother of five had a love affair with a man and that he found pictures of the woman sitting with her alleged lover."

The spokesman said the suspects "burned the victim's body and set ablaze her house to cover the crime."

"They were arrested at hospital after being treated for burns. They confessed to the murder," added.

Murder is punishable by the death penalty in Jordan but in the case of so-called "honour killings" a court usually commutes or reduces sentences, particularly if the victim's family urges leniency.

The US-based Human Rights Watch (HRW) urged Jordan earlier this month to reform its penal code, which it says condones the murder of women as "honour crimes."

In the past, parliament has refused to institute harsher penalties.

Around 15-20 women are murdered each year in Jordan in the name of honour, despite government efforts to fight such crimes. So far this year, there have been 16 reported.