Belgian police are investigating a man seen wearing a winter coat with a wire coming out of it in Brussels, Belgian federal police said.
Adding to the suspicious circumstances: Brussels is enduring a heat wave, making it questionable why anyone would wear a coat. The temperature during the police operation Wednesday was 32 degrees Celsius (90 degrees Fahrenheit).
Authorities immobilized the suspect, and anti-bomb officers are checking the winter coat.
A nearby library was evacuated as police set up a security perimeter.
Brussels has been on high alert after terror attacks killed 31 people in March. Two bombs exploded at the Brussels Airport, and a third exploded at a metro station.
ISIS claimed responsibility for the bombings, which also wounded 300 people.