BRUSSELS (AP) — Belgian prosecutors said Wednesday they have questioned four suspected Islamic State group recruiters, who may have planned new attacks in the country.

All four suspects were charged with participating in the activities of a terrorist group, the Federal Prosecutor's Office said in a statement. Two were ordered arrested by an investigating judge, but one of them was released with an electronic bracelet. The other two were released under strict conditions.

The statement said the four don't appear to have links to the suicide bombers who struck the Brussels Airport and subway on March 22, killing 32 people.

Prosecutors said initial findings of the investigation into the suspects indicated there may have been plans for attacks in Belgium, but provided no details.

Searches were carried out in the port city of Antwerp and at least two other locations, Ternat and Borgerhout.

The prosecutors said some of those detained were planning to go to Syria or Libya and join IS. All of the suspects are believed to have wanted to recruit people to go to those conflict zones, the statement said.

Belgium has been one of the most fertile recruiting areas in Europe for the extremist group, which claimed responsibility for the attacks in Brussels as well as the Nov. 13 attacks that killed 130 people in Paris.

No weapons or explosives were found in the eight sites searched on orders from an investigating judge, the prosecutors said in their statement.

They said no additional details would be made public in order not to hamper the ongoing investigation.

This story has been corrected to give accurate details about the arrests. An earlier story erroneously reported that two of the suspects were ordered arrested, one was released under strict conditions and one was released with an electronic bracelet.