German police say they have searched apartments in five regions as part of an investigation into alleged involvement in extremism by Chechen asylum-seekers.

Police in the eastern region of Thuringia said that they searched 13 dwellings in five regions as part of an investigation into a 28-year-old Russian citizen of Chechen background suspected of intending to join the fighting in Syria on behalf of the Islamic State group. The investigation later developed into a probe of 13 further individuals suspected of financing extremist activity.

Police said all were people of Chechen ethnicity with Russian citizenship seeking asylum in Germany, and whose status has not yet been decided.

Police said there was no concrete danger of an imminent attack. The statement did not say whether anyone was arrested.