German police arrested three Iraqi men Tuesday on charges that they funneled thousands of dollars to the Ansar al-Islam network to support terrorist attacks in Iraq, authorities said. It was the latest in a string of arrests of suspected Ansar operatives in Europe.

The arrests came when more than 150 police officers raided two dozen properties across Germany as well as a site in Switzerland. They were searching for evidence that Ansar was using Central Europe as a fund-raising and smuggling base for its operations in Iraq.

It was the fourth major sweep by counterterrorism agents in Germany since December, when three Iraqis were arrested and charged with planning an attack against Ayad Allawi, then Iraq's interim prime minister, when Allawi was visiting Berlin.

According to the German prosecutor's office in Karlsruhe, the arrests early Tuesday took place in Nuremberg, Munich and the town of Buehl. The suspects have been charged with raising thousands of dollars "to finance terrorist attacks" on behalf of Ansar in Iraq and "to secure the logistical and structural foundation of the group," according to a statement released by prosecutors.

Authorities did not fully identify the men, as is customary in the early stages of German criminal cases.

According to the U.S. State Department, Ansar was founded in 2001 in a merger of two radical Kurdish groups seeking to establish an Islamic state in northern Iraq. Since the U.S.-led invasion of Iraq in 2003, however, the network has established widespread roots in Europe, where it has recruited fighters and money for the insurgency in Iraq. In addition to Germany, Ansar supporters and operatives have been arrested in Sweden, Italy, Spain and the Netherlands.

Federal prosecutors said that two of the men arrested Tuesday took orders from an accused Ansar ringleader who was charged in the plot against Allawi in December. Authorities said 11 other suspected Ansar operatives were also targeted in the sweep, but were not detained or charged due to insufficient evidence.

In the southern state of Bavaria, where 135 police officers were deployed for the searches and arrests on Tuesday, officials said they seized 13 computers, identification documents and two "high-quality bicycles" that they suspect were stolen. They did not report recovering any weapons or cash.

Federal prosecutors said there was no evidence that Ansar was planning attacks in Germany.