There was no word today on the fate of 21 South Korean Christians held hostage by the Taliban in Afghanistan after the latest deadline set by the insurgents expired.
Earlier in the day, a Taliban spokesman said the group was expecting to hear from Afghan mediators over its demand for the government to release rebel prisoners, but insisted some of the hostages would be killed if that demand was not met by 8.30 a.m. Irish time.
The Afghan government has said that giving into rebel demands would only encourage more kidnapping.
The hostages' desperate relatives, keeping a vigil in Seoul, appealed to the US government to intervene. South Korean political leaders also made a joint appeal to Washington to act.
The Taliban spokesman said two women among the 21 Koreans were now seriously ill.
"The majority of the hostages are ill, but two females are seriously ill and there is this possibility that they may die," Qari Mohammad Yousuf said by telephone from an undisclosed location.
He said the pair suffered from an unknown illness and the Taliban did not have the right medicines to treat them.
The Taliban were looking after the remaining South Koreans kidnapped from a bus in Ghazni province two weeks ago, he added. The kidnappers killed two male hostages after previous deadlines expired.
Afghan officials have said no deal would be struck with the Taliban and demanded the unconditional release of the remaining captives, 18 of them women. The group of 23 had been sent by a Christian church in Seoul to do relief work in Afghanistan.
President Hamid Karzai came under sharp criticism after releasing a group of Taliban prisoners in March in return for the freedom of an Italian journalist.
South Korea is under intense pressure to bring the hostages home but concedes it has few cards to play. Seoul has called for "flexibility", a comment analysts say is directed at the United States to pressure Kabul to strike a deal with the kidnappers.
A US State Department spokesman has said Washington "does not make concessions to terrorists".
The abduction of the Koreans comes after 18 months of rising violence in Afghanistan, the bloodiest period since the Taliban were ousted from power by US-led and Afghan forces in 2001.
A day before seizing the Koreans, the Taliban abducted two German aid workers and five Afghan colleagues in Wardak province, which like Ghazni lies to the southwest of Kabul.
One German was found shot dead this week and one of the Afghans managed to escape. The other German and four Afghans were still being held. The Taliban is demanding that Germany pulls its 3,000-strong force under Nato's command out of Afghanistan as the main condition for freeing the other German.
German Chancellor Angela Merkel has said Berlin will not give in to the kidnappers' demands.