GHAZNI (AFP) - Taliban militants threatened to start killing Monday their 22 South Korean hostages if the government did not accept by noon their demand for the release of jailed rebels.
The Islamic extremists have already killed the leader of the group of Christian aid workers captured 12 days ago, saying he was shot last week because talks on Afghanistan's latest foreign hostage crisis had stalled.
The insurgents have also, however, let four other deadlines pass without incident.
Monday's 0730 GMT deadline was the last, Taliban spokesman Yousuf Ahmadi told AFP on Sunday as a stalemate emerged over the demand for a prisoner release, which a government negotiator said was not up for discussion.
"We give a last deadline of tomorrow 12 o'clock to the Afghan government to give us their last word if they can release our eight suggested prisoners."
"Otherwise we will start killing the hostages," Ahmadi said.
President Hamid Karzai said during a meeting with a South Korean special envoy Sunday that his government was doing its best to secure the release of the 22 who include 16 women.
But "no prisoners will be released," said a leading member of a government-appointed negotiating team, Mahmood Gailani, a parliamentarian from the troubled southern province of Ghanzi where the group was caught July 19.
"It's not government policy to exchange prisoners," he told AFP.
Kabul was roundly condemned when it released five Taliban prisoners in March to free an Italian hostage, and Karzai vowed afterwards such a deal would not be repeated.
Gailani said the government wanted the Islamic fundamentalists to unconditionally free the women and would then consider other Taliban demands.
The holding of women as hostages or prisoners was against Islamic law and Afghan culture, he said, a statement repeated by Karzai in Sunday's talks with South Korean presidential envoy Baek Jong-Chun.
There are concerns for the health of the 22, who were said to be in their 20s and 30s and had been on an evangelical and aid mission to devoutly Islamic Afghanistan.
"Some of the hostages have some health problems due to the weather or psychological pressure they feel," Ahmadi said Sunday with temperatures in southern Afghanistan in the high 30s centigrade (90s Fahrenheit).
The hostages had been divided into small groups and were being held in three different provinces, Ahmadi said. Medicine sent to them had been received and been passed along, another spokesman said.
Several foreigners have been seized this year by militants waging a deadly insurgency against the Western-backed government that replaced the Taliban regime driven from power in late 2001 for sheltering Al-Qaeda.
Most of have been freed, some reportedly after hefty ransom payments, although in the case of the Italian hostage, a journalist, two Afghans were beheaded.
Observers warned at the time that the move increased the threat of foreigners being kidnapped, by the Taliban or criminal gangs seeking ransom.
The militants are also holding a German engineer, kidnapped in Wardak province near Kabul a day before the South Koreans, and have also demanded the release of prisoners to save his life.
"He is sick and forgotten and there are no negotiations ongoing about him at all," Ahmadi said Sunday, although the Afghan and German governments have said that efforts are under way to help the engineer.
He was captured with a German colleague who died four days later. The Taliban said they shot him, but authorities said he died from the conditions of his detention. Four Afghans captured with the engineers are also being held.