BERLIN (AP) — Police evacuated part of a terminal at Frankfurt Airport, Germany's biggest, on Tuesday over concerns that at least one person may have entered the facility's security area unchecked.

Federal police said they stopped boarding in area A of the airport's Terminal 1 and were clearing the security area.

Police spokeswoman Julia Thiel told The Associated Press that "there were indications that at least one person entered the security area in area A without authorization, and so we have to clear the security area."

It wasn't immediately clear how many people were affected.