The Taleban have killed one of the 23 South Korean hostages they abducted in Afghanistan, government officials say.
An official told the BBC a man's body was found in Ghazni province, where the Koreans have been held for six days.
The Taleban said it had killed the man because Kabul had not met its demands, but district official Khowja Seddiqi said the hostage was too ill to walk.
South Korea condemned the killing, and said the perpetrators could not avoid responsibility for their actions.
"The South Korean government bitterly deplores the killing of a South Korean national by kidnappers in Afghanistan. The kidnappers blamed for the killing will never avoid all responsibility for that inhumane act," said a statement from the office of President Roh Moo-Hyun, quoted by AFP news agency.
Mr Seddiqi could not confirm reports that eight of the Koreans had been freed.
Meanwhile, it has emerged that an abducted journalist freed on Wednesday is Danish, not German as reported earlier.
The journalist, named Khwaja Najibullah, is of Afghan origin, and worked for Danish television. He was freed along with his Afghan driver and translator.
Speaking after his release, Mr Najibullah said his abductors had released him after pressure from local people.
'Did not listen'
Local police said the South Korean man's body had been found with multiple bullet wounds in the Mushaki neighbourhood of Qarabagh district in Ghazni province - where the Koreans are being held.
South Korean media identified the man as Bae Hyung-Kyu, 42, a church pastor and leader of the group.
Mr Seddiqi, who is head of Qarabagh district, said the man had been killed because of a failure in negotiations, or because Taleban demands had not been met.
Earlier, Taleban spokesman Qari Yousuf Ahmadi announced the killing but told Reuters news agency that the group had killed the hostage because: "Kabul's administration did not listen to our demand and did not free our prisoners".
The spokesman repeated Taleban demands that eight of its jailed fighters be released, or more hostages would be killed.
The 23 Koreans were abducted in Ghazni, south-west of Kabul, on Thursday. The hostages - most of them women - are members of a Christian aid group.
In addition to the South Koreans, two Germans were kidnapped in central Afghanistan last week. The body of one was later found by a road.