A rights group says hundreds of Afghan women are in jail for so-called moral crimes that include running away from domestic abuse.

Human Rights Watch says about 400 women and girls are being held in Afghan jails for crimes that also include having sex outside marriage.

In a new report, titled I Had To Run Away, the group says even if a woman is raped, it is she who is punished and not the perpetrator.

The group's executive director, Kenneth Roth, has called on Afghan president Hamid Karzai to immediately release them.

"It is shocking that 10 years after the overthrow of the Taliban, women and girls are still imprisoned for running away from domestic violence or forced marriage," he said.

"President Karzai could simply issue an order and say that running away from domestic violence is not a crime, period.

"The crime of running away isn't even a crime. And the Supreme Court says, 'well we based this on Sharia (law)' - but no-one else in the world, no other government treats running away from an abusive situation as a crime."

Human Rights Watch researcher Heather Barr notes that Mr Karzai does regularly issue pardons for women convicted of "moral crimes".

"But it doesn't make up for something that's an injustice in the first place," she said.

"It doesn't give you back the months or years you have spent in prison, it doesn't change the fact that so many of these women and girls are at risk of honour killings because they have been convicted of these crimes."

According to the report, many of the 58 inmates interviewed expressed fears that they could be murdered by their families for reasons of "honour" after they were released.

The report cited a woman sentenced to three years in prison after fleeing a father-in-law who raped her and had her brother murdered as saying: "I am happy in here. Here I am not afraid because I know no-one is coming in the night to kill me."

A spokesman for Mr Karzai has played down the report, rejecting suggestions the Afghan government has failed to fulfil its obligations under international human rights laws.

"Over the past decade conditions for women have significantly improved," spokesman Aimal Faizi said.

"The constitution and other laws of Afghanistan defend the rights of women."

But he added: "We can't deny there still are problems faced by women, Afghanistan is a war-torn country."

ABC/AFP