BERLIN (Reuters) - German federal police have warned parliamentarians they may have been spied on by Turkish intelligence and may also face potential security risks from Turkish nationalists, Die Welt newspaper reported on Wednesday.

The report could further strain already frayed ties between Germany and Turkey, which are at loggerheads over a wide range of issues.

“The Federal Criminal Police Office carried out so-called ‘security discussions’ with several members of parliament in recent weeks,” Die Welt reported.

“The discussions reportedly centered on the possible surveillance of Turkish intelligence and security risks posed by Turkish nationalists.”

The Federal Criminal Police Office was not immediately available to comment on the report.

Germany’s chief federal prosecutor in January launched an investigation into possible spying by clerics sent to Germany by the Turkish government, and in March opened a second, unrelated probe into suspected espionage.

At the time, German media reports said the Turkish Intelligence Agency (MIT) was suspected of spying on supporters of U.S.-based cleric Fetullah Gulen, accused by Ankara of organizing a failed coup last July.

Ties between Germany and Turkey have been strained for more than a year over issues including the German parliament’s approval of a resolution classifying the 1915 massacre of Armenians by Ottoman forces as a genocide; Berlin’s criticism of a domestic security crackdown after the July coup; and Turkey’s jailing of a German-Turkish journalist.

Germany’s parliament this month approved the planned withdrawal of troops from the Incirlik air base in southern Turkey after Ankara’s refusal to allow German lawmakers access to German soldiers there.

Turkey has also accused some German lawmakers of supporting the outlawed Kurdistan Worker’s Party (PKK), a charge they reject.