The Afghan foreign ministry is denying claims that two German hostages kidnapped by the Taleban have been killed.
A Taleban spokesman said Saturday, that militants killed the two hostages after a deadline passed for the German and Afghan governments to meet the groups' demands.
However, the Afghan government says one of the hostages died of a heart attack and the other may still be alive.
Two German engineers were abducted Thursday in central Afghanistan along with five Afghan colleagues.
The French news agency, AFP, quotes a Taleban spokesman as saying that the five Afghans were killed.
The Taleban said it would kill the hostages if Germany did not agree to withdraw its 3,000 troops from Afghanistan. The militants also demanded that all Taleban prisoners held in Afghanistan be released.
Earlier Saturday, German Chancellor Angela Merkel rejected the Taleban ultimatum for German forces to pull out of the country. Germany's foreign ministry said it is taking the claims "very seriously."
In another development, South Korea reaffirmed plans to withdraw its 200 troops from Afghanistan by the end of the year.
The announcement came a day after Taleban insurgents abducted at least 18 South Koreans, and said they would be released only if Seoul withdrew its troops from Afghanistan.
The South Korean Christian evangelists were abducted when insurgents stopped their chartered bus, which was driving from the capital, Kabul, to southern Kandahar province.
Some information for this report was provided by AFP, AP and Reuters.