German Foreign Minister Frank-Walter Steinmeier confirmed Saturday that one of the two German hostages kidnapped in Afghanistan is dead and German government is doing everything it can to save the other.

Steinmeier said the hostage is apparently not murdered by the kidnappers, as previously claimed by a Taliban spokesman.

"Now we have to do everything we can, with all the responsibility, to save the life of the second hostage," said Steinmeier.

Earlier, an Afghan foreign ministry spokesman said in Kabul that one of the German hostages died of heart attack and the other is still alive.

Steinmeier told reporters that a German crisis team is still trying to analyze the conflicting information from Afghanistan and German government has "deepest concern" over the fate of the German hostages.

Meanwhile, the minister condemned the way the extremists "instrumentalize" the lives of the innocent German engineers who are only in Afghanistan to help rebuild the war-ravaged country.

A purported Taliban spokesman Yousuf Ahmadi said earlier Saturday that Taliban fighters had executed two German hostages after the German government failed to meet their demands.

The first hostage was shot dead in Afghanistan's central Ghazni province shortly after the Taliban's 12:00 p.m. (0730 GMT) deadline Saturday expired, Ahmadi said. The second hostage was killed about one hour later.

The Taliban has demanded the departure of all German soldiers from Afghanistan and the release of captured Taliban militants.

German Chancellor Angela Merkel reaffirmed Friday that Germany will not withdraw its troops from Afghanistan.

Germany now has about 3,000 soldiers stationed in Afghanistan under the command of the NATO-led International Security Assistance Force (ISAF), most of them in the relatively stable northern region.

The two German nationals and five of their Afghan colleagues, who are civil engineers working on a dam project in Afghanistan, were reportedly abducted Wednesday in Wardak province, about 100 kilometers southwest of Kabul.