The women were said to be ill but were able to walk to freedom

The pair, both women, were brought to a meeting point pre-arranged with the Taleban and handed to the International Committee of the Red Cross.

They were said to have been released partly because they were in poor health and partly as a goodwill gesture after talks with South Korean officials.

Two of the 23 South Koreans captured three weeks ago have been killed.

The location of Monday's release was close where the bodies of the two male hostages were found last month, says the BBC's Charles Haviland in Kabul.

South Korea's foreign ministry confirmed that the two women had been freed.

'Heavy heart'

The two women, who were wearing headscarves and were in tears, got into the ICRC car and were driven to the nearby town of Ghazni, our correspondent says.

I have a very heavy heart rather than have a happy heart Sun Yun-ja Mother of a released hostage

There, they were expected to meet South Korean delegates who have been negotiating with two Taleban officials to secure the hostages' release.

An ICRC official told the BBC the Taleban had earlier contacted the organisation to request that it play a role in the handover. He said the ICRC would willingly repeat such a role if requested.

The women, who were photographed walking to the car, were said to be in "fair" health, our correspondent says.

The mother of one of the released hostages, Sun Yun-ja, said it was difficult to be happy about the releases.

"Two came back as bodies, two will return as being sick - I am really sorry for the family members of the remaining 19 hostages."

"I have a very heavy heart, rather than have a happy heart."

Christian captives

There had been confusion over the releases, with a Taleban spokesman telling reporters on Saturday that the two had already been freed, before saying the timing of the release had yet to be decided.

A new timing of 1130 GMT Monday, announced by the same spokesman, Yusuf Ahmadi, then passed with no news of any hostage releases.

The Taleban said the two women were released because they were sick and as a goodwill gesture.

They say they want Taleban imprisoned by the Afghan government to be set free if the other Koreans, most of whom are women, are to be released.

The South Koreans, all Christian aid workers, were seized on 19 July.

The original group of 23 - most of them women - was captured on the main road from Kabul to Kandahar.

It is thought the remaining South Korean hostages are being held in a number of small groups in a village about 10km (six miles) from Ghazni.