A Taliban spokesman says 18 South Korean civilians they kidnapped will be killed, unless the Asian country withdraws its 200 troops from Afghanistan by Saturday at noon.
Taliban gunmen boarded the busy carrying the South Korean Christians and took them prisoner on Thursday. Fifteen of the 18 passengers on the bus were women.
Qari Yousuf Ahmadi, who claims to speak for the Taliban, spoke to The Associated Press on a satellite telephone from an undisclosed location.
"Right now they are safe and sound," he said.
The South Koreans were in Ghazni province, travelling from Kabul to Kandahar when the bus was boarded, Ali Shah Ahmadzai, the provincial police chief, told AP.
According to reports, all were Christian members of a South Korean church and were doing volunteer work in Afghanistan, against their government's urgings.
South Korea's Yonhap news agency reported on Friday that they were members of Saemmul Community Church in Bundang, near Seoul.
CTV's Denelle Balfour, reporting from Kandahar, said the Koreans arrived in Afghanistan last Friday and had been volunteering in a hospital. They were scheduled to head home next week.
A church official has confirmed that 20 of its members were doing volunteer work in Afghanistan and that they have been unable to contact them.
The driver of the bus was released late Thursday. He said there were 18 women and five men on the bus, but there was no explanation of the discrepancy between those provided by the Taliban.
South Korea has about 200 troops serving with a U.S. forces, in operations separate from the 40,000-member NATO-led force.
This represents the largest abduction of foreigners since the fall of the Taliban in 2001.
