The Taliban movement in Afghanistan set 4:30 am on Thursday (Bejiing Time) as the last deadline for its South Korean hostages, a spokesman said after reporting the group had shot dead one of the 23 captives.

Family members of the South Koreans kidnapped in Afghanistan watch television news in Seoul July 24, 2007. [Reuters]

"If the administration of Kabul is not ready to release our hostages, then by 1:00 am (local time) the rest of the hostages will be killed," Taliban spokesman Qari Mohammad Yousuf told Reuters by telephone from an unknown location. "That time is the last deadline."

Purported Taliban spokesman Qari Yousef Ahmadi claimed that one of the hostages had been shot and killed around 4 p.m., and a police official who asked not to be identified because of the sensitivity of the situation said militants told him the hostage was sick and couldn't walk and was therefore shot.

The Associated Press reported a group of abductees was freed and taken to a US military base, citing officials.

Some of the 23 Korean hostages, meanwhile, had been freed and were taken to a US base in Ghazni, two Western officials said who asked not to be identified. The officials did not know how many had been freed. The South Korean news agency Yonhap said eight Koreans had been freed.

Afghan President Hamid Karzai has pledged not to swap prisoners for hostages after being heavily criticised both at home and abroad for releasing five Taliban from jail in March in exchange for an Italian reporter.

The kidnappings have made travel outside major cities risky for the thousands of foreign aid workers and United Nations staff in Afghanistan and may weaken support for military involvement among the more than 30 nations with troops in the country.

The 23 Korean church volunteers -- 18 women and five men -- were seized in Ghazni province on the main road south from Kabul last week.

Elsewhere in Afghanistan, a German journalist and his Afghan translator kidnapped in the east of the country overnight were freed on Wednesday.

One other German and four Afghans abducted last week are still in captivity.