The Wall Street Journal reports: A man who was detained in France and exposed an Islamic State terror cell in Germany told authorities that the cell contained many more people than the three arrested last week, according to officials familiar with his testimony.

The revelations, part of new details emerging about the arrested suspects, add to concerns that the extremist group could be poised to strike again in Europe.

Authorities in France, Germany and the Netherlands are examining testimony from Saleh A., who walked into a police station in the north of Paris in February claiming that he was part of an Islamic State sleeper cell of between 10 and 20 people, officials familiar with the investigation said. Based on his testimony, German police last week arrested three suspected Islamic State members who arrived in the country among Syrian asylum seekers on suspicion of preparing an attack in the western Germany city of Düsseldorf.

“Saleh A.’s statements are central” to the investigation, one German official familiar with the investigation said. German and French authorities have worked closely together on the case, the person said, adding that German investigators had been able to question Saleh A.

Saleh A. told French police that his terror cell was awaiting instructions from a certain Abu Doujana Al Tunisi, supposedly the head of foreign fighters for Islamic State, and that around 20 people were members of the cell, according to a French official. Another official familiar with the probe said Saleh A. had told investigators about 10 people would participate in the attack in Düsseldorf. [Continue reading…]