Germany's federal police on Sunday announced the arrest of a French national suspected of fighting for radical jihadists in Syria.
A spokesman told AFP that the man was picked up in Berlin late Saturday after flying in from Istanbul and was believed to have spent time in Syria where he allegedly joined the jihadist Islamic State of Iraq and the Levant, also known as ISIS.
He confirmed a report in the daily Frankfurter Allgemeine Zeitung, which said the man, who was not named, was injured while fighting in Syria and posted several pictures of himself with gunshot wounds on Islamic extremist websites.
The report added that German authorities believe the man was returning to Europe to recruit other fighters for Syria or plan an attack.
The spokesman declined to comment, saying that the federal police would release further details on Monday.
"We need to exchange some information with international partners first," he said.
The arrest came three weeks after a deadly attack on the Jewish Museum in Brussels, which police suspect was carried out by a Franco-Algerian who spent more than a year fighting for ISIS - a breakaway faction of Al Qaeda - in Syria.
It also comes one day after an possible terrorist attack against a synagogue in Paris was thwarted. Two men approached the building in the French capital's 20th District armed with an assault rifle and a pistol, but after threatening passersby beat a hasty retreat when they noticed French policemen stationed nearby. The identities of the would-be attackers is not yet known.
The French government unveiled an anti-terrorism plan in April to prevent the radicalization of nationals, thwart online recruitment and make it more difficult for aspiring jihadists to leave the country for Syria.
The German domestic security watchdog warned recently of the threat posed by Islamic extremists returning from fighting in the Syrian civil war.