BERLIN (AP) — Three teenagers suspected of planning an Islamic extremist attack have been arrested in western Germany, prosecutors said Friday.

The trio — two girls who are 15 and 16, and a 15-year-old boy — come from various parts of North Rhine-Westphalia state, Germany’s most populous. They were arrested after a court issued warrants over the Easter weekend, prosecutors in Duesseldorf said.

They are suspected of having declared themselves prepared to carry out an “Islamist-motivated terror attack” and planning such an attack, prosecutors said in a statement. They didn’t specify how advanced the plans were, and said they couldn’t give further details because of the suspects’ young age and the ongoing investigation.

The three are in detention pending possible charges of declaring themselves ready to commit murder and manslaughter and preparing a serious act of violence.

German news agency dpa, citing unidentified security sources, reported that the teenagers had set up a chat group and that they hadn’t yet drawn up a concrete attack plan with a time and place.