Protesters hold pictures of 21 South Korean hostages held in Afghanistan during anti-war and anti-US rally, 01 Aug 2007

The Taleban militant group says the 21 remaining South Korean hostages in Afghanistan are still alive, but it is possible they will be killed.

A Taleban spokesman made those remarks Wednesday, shortly after another deadline imposed by the group passed. The spokesman also warned any rescue operation would jeopardize the hostages' lives.

The Afghan military has dropped leaflets warning of a possible military operation in Ghazni province, where the Taleban is suspected of holding the South Korean hostages. But Afghan officials say the leaflets refer to a routine operation not related to the hostage situation.

The kidnappers have already killed two South Korean hostages. The Taleban say more will die unless the government exchanges Taleban prisoners for the captives. The Kabul government has refused the demands.

In Seoul, relatives of the hostages made an emotional appeal to the U.S. embassy for help in negotiations.

Earlier, a U.S. State Department spokesman, Tom Casey, said there is regular contact between U.S. and South Korean officials on the crisis, but he did not elaborate.

Twenty-three South Korean Christian volunteers were abducted July 19th while traveling by bus to southern Kandahar province, a Taleban stronghold. The bodies of two of them, identified as Shim Sung-min and Bae Hyung-ku, were found in Ghazni.

Some information for this report provided by AP, AFP and Reuters.