The Taliban has freed 12 South Korean hostages in Afghanistan on Wednesday, a day after reaching a deal with negotiators on the release of the 19 Christian volunteers.

|PIC1|Three South Korean women were released first, followed by four women and a man -- handed over to members of the International Committee of the Red Cross (ICRC) in Ghazni province, Reuters witnesses said.

A third batch comprising three women and a man were released later on Wednesday, they said.

All 12 hostages were said to be in good health, with the last group of four said to be "hugely relieved" at their release.

Taliban militants have begun releasing the South Korean hostages following an announcement on Tuesday that all the Christian volunteers would be freed in exchange for the withdrawal of South Korean troops from Afghanistan.

Wearing long, traditional headscarves, the three women who were first to be freed wept as they sat in an ICRC vehicle.

A Taliban spokesman, Qari Mohammad Yousuf, said by telephone he expected all of the hostages to be free by Thursday.

Family members cried out with joy and hugged one another when they were told of the hostages' imminent release on Tuesday.

After the initial euphoria, the relatives apologised to the nation for the trouble that the Saemmul Church had caused to South Korea by sending the team of young and mainly female Christian volunteers into one of the most dangerous countries in the world.

The team of medical volunteers originally numbered 23. In the six weeks since they were abducted from a main road south of Kabul last month, two male hostages were killed by captors, while two female members were released earlier in the month as a "gesture of goodwill".

The release of the remaining 19 hostages caps weeks of on-off negotiations between the Taliban and South Korean officials, which appeared in deadlock just days before.

"The families are rejoicing at the news. They are busy calling other family members and friends at the moment to pass on the news," Bang Yong-kyun, pastor at Saemmul Church, told Reuters.

"We knew the negotiation process was turning favourable, but we never thought it would happen so soon," a spokesman for the hostage families, Cha Sung-min, told reporters.

"When the announcement came out, there was a commotion in the room as everyone hugged each other."

Pastor Bang shared the excitement felt by all the relatives at the prospect of their loved one returning home.

"We will do what we weren't able to do during the incident. We found out that the everyday routines were the most precious moments. Eating breakfast together or having slices of fruit after dinner," he said.

"Those insignificant things are what we treasure the most."