German police on Tuesday said they were investigating two men of Tunisian origin suspected of involvement in a plot to carry out terrorist attacks using remote controlled airplanes.

While authorities believe the two were motivated by radical Islam, they are not considered to be members of an established terrorist group, according to Der Spiegel.

The German Federal Public Prosecutors’ Office issued a statement saying the men are suspected of “procuring information and objects to commit Islamic extremist explosive attacks with remote-controlled model airplanes.”

German Police Bust Radical Islamist Model Airplane Terror Plot

Members of a special response unit of the German state police leave the site of a search operation in Fellbach, Germany, Tuesday, June 25, 2013, as German prosecutors said they are investigating two men suspected of planning terrorist attacks using model airplanes. Authorities in Germany and neighboring Belgium conducted a series of searches of nine properties in Germany and Belgium. (AP Photo/dpa, Franziska Kraufmann)

According to Der Spiegel, apartments in three German states were searched as well as a site in Belgium.

The German news agency DPA reports that German authorities had recently detected “an increased interest in explosives and model aircraft.”

Der Spiegel provides more information from the prosecutor’s statement:

The statement claims that no arrests were made on Tuesday morning, though pictures from the raid show a man in Baden-Wurttemberg being taken into custody. A total of nine buildings were searched, including apartments belonging to four suspected accomplices of the two Tunisians in Munich and Stuttgart. The four are thought to have “provided financing for the militant jihad,” the federal prosecutors’ statement reads. An additional suspect is thought to have engaged in money laundering.

Spiegel quotes Stuttgart public broadcaster SWR which reports that some of the suspects are students at the University of Stuttgart studying aerospace engineering. In those courses, they learn how to program model airplanes to fly to a specific location using GPS.

The Associated Press reports that some 90 police officers took part in the searches.

This plot comes on the heels of previously reported attempts to use remote-controlled airplanes as a terrorist weapon. Earlier this month, Iraq officials said they had prevented an Al-Qaeda plot using toy planes to drop chemical agents, including sarin and mustard gas, over Europe and North America.

Rezwan Ferdaus of Massachusetts is serving a 17 year prison sentence for plotting to load explosives onto model airplanes and attack the Pentagon and the U.S. Capitol. Media reports said the 27-year-old with a college degree in physics was motivated to carry out “holy war” on the United States after being influenced by jihadi websites.

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