In a new video released on Wednesday, two German-speaking members of the "Islamic State" (IS) group threatened the country with attacks.

From the ruins of the world heritage city of Palmyra, the bearded men also called on "brothers and sisters" to join IS in its mission to carve out a caliphate in Syria and Iraq. The men told those who could not travel to carry out attacks on the group's behalf in Germany and Austria - striking "nonbelievers" at home.

Switching between German and Arabic, one of the men also called out Chancellor Angela Merkel personally for her support of coalition efforts to rid Syria and Iraq of the group. At the end of the video, the believed combatants appear to kill two unknown men kneeling among the ruins.

According to the most recent estimates, about 600 people have left Germany to join IS or groups like it in Iraq and Syria.

Arrest near Stuttgart

On Wednesday, German police arrested a 21-year-old Moroccan man at a home for asylum applicants in Ludwigsburg, near the southern city of Stuttgart, on suspicion of supporting IS. According to the results of an investigation, the man had also applied for asylum under a false name.

Spanish police had already issued a warrant for the man, who is suspected of attempting to recruit Europeans to fight for IS. He had allegedly served as a point of contact in Spain for recruits en route to the Middle East, and is said to have threatened the country with attack over social media.

Elsewhere, a North African IS offshoot group has threatened to kill a Croatian man kidnapped in Cairo unless Egypt releases certain female Muslim prisoners. And British officials have charged a preacher with trying to grow support for IS.

At meetings in the Middle East on Wednesday, officials from Russia and the United States agreed that IS is a common enemy of the two power rivals.

mkg/cmk (AFP, dpa)