German police carried out raids on suspected Islamist militants across the country early Tuesday, over allegations they were plotting a violent attack, Berlin prosecutors said.
German authorities are on high alert for Islamist threats to Europe's most populous country, which has in recent years suffered several attacks.
"On suspicion of planning a serious violent act endangering the state, search warrants are being executed in Berlin, Brandenburg, North Rhine-Westphalia and Thuringia," the Berlin attorney general's office said via Twitter.
The probe "targets suspects of Chechen origin from the Islamist scene," it later added.
Germany's deadliest attack was a truck rampage through a Berlin Christmas market in December 2016 that left 12 people dead.
The attacker, Tunisian asylum seeker Anis Amri, hijacked a truck and murdered its Polish driver before killing another 11 people and wounding dozens more by ploughing the vehicle into a festive market in central Berlin.
He was shot dead by Italian police in Milan four days later while on the run.
Since then, German authorities have thwarted nine attacks believed to have radical Islamist motives, according to the head of the Federal Crime Office (BKA), Holger Muench.
Most recently, police in the western city of Offenbach arrested three men in November 2019 for allegedly planning a bomb attack in the name of Islamic State.
That same month, a Syrian was arrested in Berlin accused of having procured key components for an explosive device and discussing bomb-making tips with other suspected Islamists in an online chat group.
Germany's security services estimate there are around 11,000 Islamic radicals in Germany, some 680 who are deemed particularly dangerous and capable of using violence -- a five-fold increase since 2013.
Around 150 of these potentially dangerous individuals have been detained for various offences.
