July 21 (Bloomberg) -- A German hostage kidnapped in Afghanistan has died while a second is still thought to be alive, German Foreign Minister Frank-Walter Steinmeier said.

``We have to assume at this point that one of the hostages has died in captivity,'' Steinmeier told reporters in Berlin today. After analyzing all the information from the region, it appears that the hostage died of a heart attack and was not murdered, he said.

``We will do everything possible to save the life of the second hostage,'' he said, noting that at least 18 South Koreans are also being held captive in Afghanistan after going missing on July 19.

Steinmeier was responding to reports that Taliban insurgents had captured and killed the two Germans after the Afghan and German governments failed to make contact for negotiations. Taliban spokesman Yousuf Ahmadi said yesterday that the two would be killed unless Germany withdraws its military forces from Afghanistan, news agency Deutsche Presse- Agentur reported.

The two Germans, who worked for a company in the capital Kabul, went missing in Wardag province, west of the capital Kabul on July 18, according to the Foreign Ministry. Both were engineers, news magazine Der Spiegel reported today. The dead man came from the eastern state of Mecklenburg-Western Pomerania and suffered from diabetes, Spiegel said.

Terrorism Threat

The German government, which has deployed more than 3,000 troops in Afghanistan to help combat the Taliban, said last month that its military and humanitarian involvement in the country was causing a greater terrorism threat both in Afghanistan and at home. About 500 German civilian aid workers are also in Afghanistan.

Chancellor Angela Merkel postponed her ``summer interview'' with ARD television until tomorrow ``because of the turn of events in Afghanistan,'' ARD said in an e-mailed statement. Steinmeier said he is in regular contact with Merkel over the kidnappings.

Merkel said on July 18 that the country's military forces should remain in Afghanistan and that lawmakers must back an extension of the parliamentary mandates for the troop deployment. A parliamentary vote is due some time in October.

The abduction is the second incident involving a German national in the last month, after an unnamed worker went missing on June 28. The man, also an engineer, was released unharmed on July 5 after his employers paid a ransom of about $40,000, Der Spiegel reported.

South Koreans

South Korea's president, Roh Moo Hyun, today urged the immediate release of the South Koreans kidnapped in Afghanistan. ``In no instance, should there be any harm to innocent lives,'' Roh said in a televised speech. ``The abductors must return our people safely and as soon as possible.''

South Korean Foreign Minister Song Min Soon said the kidnappers were believed to be Taliban, but that he had no confirmation of that. Reuters reported local Taliban commander Mohammad Sharif took responsibility for the kidnapping.

South Korea's Foreign Ministry today issued a ``travel ban'' on Afghanistan, the highest of four travel safety levels. The government already prohibits its nationals from traveling to Iraq and Somalia.

To contact the reporter on this story: Patrick Donahue in Berlin at pdonahue1@bloomberg.net; Kenneth Wong in Berlin on kwong11@bloomberg.net.

Last Updated: July 21, 2007 14:36 EDT