The Kurdistan Workers Party rebel group seized the three Germans at Mount Ararat in eastern Turkey last Tuesday. The group, also known as PKK, has bases in northern Iraq. Turkish paramilitary troops have launched a sweep to rescue the three men and Mount Ararat has been was declared off-limits until further notice.

A spokeswoman for the group there says the hostages are being held to protest German pressure on PKK supporters in Germany. Spokeswoman Sozdar Avesta says international mediators such as the Red Cross should organize a cease-fire in the area where the climbers were kidnapped. She spoke Sunday at the Qandil mountain range, where PKK leaders are based.

The group also said Sunday it was "strong enough" to hit German economic targets, an agency close to the group reported.

The group also renewed a call on Berlin to end "hostile" policies towards the group in return for the release of the three climbers.

German Government target, not Germans

The PKK statement, carried by the Firat news agency, singled out Chancellor Angela Merkel's government as the target of the hostage-taking, saying that the group harbored no ill feelings against Germany as a nation.

"Had we had (such feelings) we could have inflicted greater damage to German economic interests in Turkey... We are strong enough to inflict such damage," it said.

"The Merkel government, together with the Turkish government, must give up sacrificing the Kurdish people's freedom struggle in the name of certain economic interests," it added.

The Germans who were seized on Tuesday were part of a tourist group climbing Mount Ararat, believed to be the final resting place of the Biblical Noah's Ark.

'Hostile' policies

The rebels said they would keep the hostages unless Berlin ended a crackdown on PKK militants and their supporters in Germany, which is home to about 2.4 million immigrants from Turkey, including about 600,000 Kurds.

Last month, German authorities banned the Danish-based Roj-TV from broadcasting in the country because it promoted the PKK. They also ordered a production house be closed that supplied the channel with programming.

In an interview with Germany's Bild newspaper Sunday, Merkel issued a personal appeal for the immediate release of the hostages, saying that Berlin would not allow itself to be blackmailed.

The PKK is considered a terrorist organisation by Ankara, the European Union and the United States. It has fought for self-rule in Turkey's Kurdish-majority east and southeast since 1984 in a conflict which has claimed more than 37,000 lives.

The group has in the past kidnapped people, among them soldiers, police officers and tourists, but it is not a tactic it frequently employs.