Afghan doctors delivered medicines on Sunday for 21 South Koreans kidnapped by Taliban rebels in Afghanistan more than two weeks ago.

|PIC1|The head of a private Afghan clinic said his team had dropped more than $1,200 worth of antibiotics, pain killers, vitamin tablets and heart pills in an area of desert in the Qarabagh district of Ghazni province as instructed by the rebels.

"This is a big achievement. Among the Koreans are doctors who know how to use these medicines," Mohammad Hashim Wahaj told reporters in Ghazni, the main town of the province where 23 South Korean church volunteers were snatched from a bus on July 20.

"It was a big risk, but we had to take the risk because it is a humanitarian issue," he said.

The Taliban have killed two of their captives and are threatening to kill the rest if the Afghan government fails to release rebel prisoners.

Kabul has refused to free jailed Taliban, saying that would just encourage more kidnappings.

The hostage issue is likely to cast a shadow over two days of security talks between Afghan President Hamid Karzai and U.S. President George W. Bush due to begin at the U.S. presidential retreat, Camp David, later on Sunday.

Wahaj said he had been in contact with the kidnappers who told him two of the remaining hostages were seriously ill. The Taliban were willing to free those two hostages, he said, but only if two Taliban prisoners were also freed.

The insurgent demand for prisoners to be released has proved a sticking point in all negotiations so far.

"WE DON'T WANT TO DIE"

A woman who identified herself as Lim Hyun-joo, a 32-year-old nurse and the group's guide who speaks the local Dari language, pleaded for help from U.N. Secretary General Ban Ki-moon, himself a South Korean.

"Every day it's really hard to survive. We really want to go home. We are all sick and weak," she told Voice of America radio. "We are innocent people. We came here to help the people, but now we are all sick ... Dear Mr General Secretary Ban Ki-moon please save us ... We don't want to die."

The South Korean government is under intense domestic pressure to secure the release of the hostages, but Seoul has told the insurgents there is a limit to what it can do as it has no power to free prisoners in Afghan jails.

A South Korean delegation was in Ghazni seeking face-to-face talks with the kidnappers to try to break the deadlock.

But the Taliban said on Sunday there was no agreement on where to hold direct talks with the Korean diplomats.

The Taliban want negotiations in areas they control or with U.N. guarantees for their safety if held elsewhere.

"Talks and contacts are still going on to decide on a venue for talks, but there has been no agreement," Taliban spokesman Qari Mohammad Yousuf said by telephone from an unknown location.

A day before the Koreans were seized, Taliban rebels in Wardak province, north of Ghazni, kidnapped two German engineers and five Afghans.

One of the Germans suffered a heart attack and was shot dead and one of the Afghans managed to escape. The rest are being held by the Taliban who are demanding Berlin withdraw its 3,000 troops from Afghanistan. Germany refused to do so.

Yousuf said he was surprised that no one was actively seeking the German's release and said the man was suffering from diabetes and was unable to receive the right medication.