11 people were arrested in western Germany on suspicion of planning an Islamic extremist terror attack but were then ordered released after no weapons or explosives were found during searches, German law enforcement officials said Saturday, according to The Associated Press.
The suspects were reportedly taken into custody on Friday and Saturday in the towns of Essen, Duesseldorf, Wuppertal, Moenchengladbach, Duisburg and Ulm.
The prosecutors' spokesman was quoted as saying Saturday that the group was suspected of having ties to Islamic State (ISIS) jihadists, either as sympathizers or a splinter group, and of planning a "serious act of violent subversion," although there was no indication of a specific target.
The prosecutor's office said the suspects were ordered released but the investigation would continue.
Germany has been on a high level of alert due to a series of terrorist attacks in the country in recent years.
In one attack, a 17-year-old Afghani with an axe attacked passengers on a train in Wurzburg before being shot dead by security forces.
In a second incident, an attacker set off a bomb in a restaurant in Ansbach, killing himself and wounding 12 others.
The worst such attack took place in December of 2016, when Tunisian terrorist Anis Amri killed 12 people and injured dozens more when he drove a truck into a Christmas market in Berlin.
In June of 2017, German authorities arrested a Tunisian man on suspicion of trying to build a biological weapon using the deadly poison ricin.