Kim Kyung-ja (left) and Kim Ji-na were freed earlier this week

Two South Korean hostages held for almost a month by Taleban insurgents in Afghanistan have arrived back home.

The two women were freed on Monday after South Korean negotiators held direct talks with their Taleban captors.

They were part of a group of 23 South Korean Christian volunteer aid workers seized on 19 July.

Nineteen members of the group are still being held hostage. The Taleban have killed two male hostages.

Taleban officials said that they released the two women partly because they were in poor health and partly as a goodwill gesture.

'Sincerely apologise'

The two women, Kim Kyung-ja, 37, and Kim Ji-na, 32, received medical check-ups in Afghanistan before flying home to South Korea.

They spoke briefly to journalists after arriving at Incheon airport near Seoul.

"I want to thank the Korean government and the Korean people for their concerns and sincerely apologise for causing such worries," Kim Kyung-ja said.

"I hope for safe release for the rest of our team members as well," she said, a statement echoed by Kim Ji-na.

The South Koreans were seized in Ghazni province as they travelled by bus along the main Kandahar to Kabul highway.

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

South Korean President Roh Moo-hyun has urged increased efforts to secure their return.