Federal authorities are investigating leads that the March 11 terrorist attacks in Madrid may have been carried out by Islamic extremists living in Germany.
A man suspected of involvement in the bombings allegedly lived in Germany.
A spokeswoman for German Federal Prosecutor Kay Nehm confirmed on Friday that Nehm has opened an investigation after agents searched an apartment in Darmstadt in the central German state of Hesse.
A man arrested in Spain and suspected of involvement in the Madrid attacks allegedly lived there for several years. Born in 1975, the man began studying electrical engineering in Darmstadt in late 2003, according to news reports.
Citing unidentified sources close to Germany's Federal Intelligence Service (BND) and the Federal Office of Criminal Investigation (BKA), the private news channel N-TV also reported that the attacks in Madrid are believe to have been carried out by men who had been registered as living in the suburban area surrounding the cities of Frankfurt and Mainz for a number of years. According to the report, the suspects had long been identified by authorities as Islamic extremists and potential terrorists. N-TV quoted a prominent German terrorism expert stating that investigators were following leads in a number of German states.
The cable network, a German affiliate of CNN, said Spanish investigators had discovered the link after arresting three Moroccan suspects on Wednesday. Police believe the men have connections to the Hamas terrorist organization and other extremist groups. N-TV said the men were believed to be "jihadis" and had been known to authorities as extremists who were thought to be especially dangerous and capable of violence. The men were reportedly legal residents of Germany.
But German daily Süddeutsche Zeitung on Friday reported that the man living in the Darmstadt apartment had not been a known extremist. The paper also wrote that earlier reports that more than one man had lived in Germany could not be confirmed.
The presence of Islamic extremists has been a dominant political issue in Germany since it was discovered that several perpetrators of the Sept. 11 terrorist attacks in the United States had been students in Hamburg. Following the Madrid attacks earlier this month, politicians in Germany have mulled changes to the law that would make it easier to deport suspected terrorists from the country.
In addition to the three arrests on Wednesday, Spanish police took another two men into custody on Thursday, bringing the total number of arrests to 18. A total of 190 people died in the March 11 bombings of commuter trains in Madrid -- the deadliest act of terror in Europe since Pan Am Flight 103 was blown out of the sky over Lockerbie, Scotland in 1998, killing 270.