BERLIN (Reuters) - German authorities have received specific warnings of the risk of militant attacks on central railway stations in Berlin and Dresden, security sources told Reuters on Friday, after pre-dawn police raids on 12 homes linked to radical Islamists.
"We've been tipped off about possible attacks on these rail stations," one source said. The warning came from foreign intelligence agencies, according to Der Spiegel news magazine.
The source told Reuters that weekly marches in Dresden by the anti-Islam, anti-immigration movement PEGIDA were considered especially vulnerable. The rallies take place near the Dresden rail station and have drawn crowds of around 25,000.
The warnings highlight a state of heightened alert in Europe after Islamist militants killed 17 people in attacks in France last week, including on the weekly newspaper Charlie Hebdo which had published caricatures of the Prophet Mohammad.
Belgian police killed two suspected Islamists in a shootout on Thursday and are questioning 15 others over an alleged plot to murder police officers across the country.
The German Interior Ministry declined to confirm or deny concrete warnings but an official pointed out that authorities are now receiving a large number of tips from a variety of sources, in part as a result of the deadly attacks in France.
"German security authorities are doing everything they can to protect the public as effectively as possible," said Interior Minister Thomas de Maiziere, responding to the magazine report. Not all protective measures are visible to the public, he added.
Der Spiegel said foreign intelligence agencies intercepted the information from jihadist groups. "We're taking these tips seriously," a high-ranking security official was quoted as saying.
Earlier on Friday, German police said they had arrested two people after 250 officers raided 12 homes, targeting a mosque group linked to radical Islamists.
The arrests followed investigations which have been going on for several months into five Turkish citizens aged 31 to 44, who are suspected of "preparing a serious act of violence against the state in Syria" and money laundering, police said.
A police spokesman said the suspects were probably part of an extremist cell that had recruited fighters for Syria. Martin Steltner at the public prosecutors' office said the raids were unrelated to the Islamist militant attacks in Paris last week.
"It must be said very clearly that there is no connection to the attacks in Paris and there are no indications that attacks were planned in Germany," said Steltner.
Police said one of the men arrested was the leader of a group of Turkish and Russian citizens of Chechen and Dagestani origin who had radicalized the group through lessons on Islam, while the other was responsible for the group's finances.
Additional reporting by Michelle Martin and Oliver Barth; Writing by Erik Kirschbaum; Editing by Stephen Brown and Mark Trevelyan