BERLIN — Three Syrian men who entered Germany with a wave of migrants were arrested Thursday on suspicion of planning an Islamic State attack on the city of Dusseldorf, potentially thwarting a deadly operation that appeared eerily reminiscent of the recent assaults on Brussels and Paris.
The suspected plot, German authorities said, involved suicide bombers, firearms and explosives — a lethal combination that has become the hallmark of a new spate of Islamist terror in Europe. A fourth man, who prosecutors said had informed French officials about the alleged plot, was being held in France.
The arrests highlighted the significant threat to Europe from Islamic State militants posing as migrants. Officials said all four Syrians entered the continent from the Middle East using the same irregular passages by land and sea — Greece via Turkey and then through the Balkans — used by hundreds of thousands of asylum seekers last year. After the attacks in Brussels and Paris, Islamic State officials have claimed that more sleeper cells were incubating in Europe. Thursday’s arrests suggested such threats were not idle.
The German chief prosecutor’s office said in a statement that there were no immediate indications that the men had started taking concrete steps to carry out the plot. But the authorities moved in on Thursday — arresting the men in three German states — after details of the alleged plot were provided by the suspect in France, who first approached authorities in Paris in February.
