Taliban kidnappers and Afghan negotiators resumed talks to free 22 South Korean hostages who were still alive on Monday despite two rebel deadlines expiring.

"The talks and dialogue are going on to persuade the Taliban to release the hostages ... and no incident has happened (to the hostages)," said deputy Interior Minister Munir Mangal, who also heads a government team tasked to release the Christian captives.

Earlier, the Taliban extended its "final" deadline at the request of Afghan mediators, but insisted the release of Taliban prisoners was the only way to settle the crisis.

When asked by Reuters if the government would bow to the Taliban demand, Mangal said "all options" were under deliberation.

Taliban members were not available for comment after the second deadline expired at 1130 GMT.

Monday's first deadline was issued by the Taliban leadership council, led by elusive Taliban chief Mullah Mohammad Omar, which gave the threat to kill the hostages more weight than several other deadlines that have passed without incident.

The Taliban seized the Korean Christians, most of them women, 11 days ago from a bus in Ghazni province to the southwest of Kabul and killed the leader of the group on Wednesday after an earlier deadline passed.

On Sunday, the Taliban ruled out further talks after they said government negotiators demanded the unconditional release of the hostages and a senior Afghan official said that force might be used to rescue them if talks failed.

The Afghan government had wanted the Taliban to first release the 18 women hostages, but the insurgents demanded the government release its prisoners first, leading to deadlock, said a Kabul-based Western security analyst, speaking on condition of anonymity.

President Hamid Karzai has remained silent throughout the hostage ordeal, except for condemning the abduction, the largest by the Taliban since U.S.-led forces overthrew the movement's radical Islamic government in 2001.

He came under harsh criticism for freeing a group of Taliban in March in exchange for the release of an Italian journalist.

The abduction of the Koreans came a day after two German aid workers and their five Afghan colleagues were seized by Taliban in neighbouring Wardak province.

The body of one of the Germans has been found with gunshots and the Taliban still hold the other along with four Afghans.