Unknown posing as a police officer.

An armed man who took on Tuesday dozens of people as hostages in a bus in Rio de Janeiro and threatened to set fire to the bus, seized by police, law enforcement agencies in Brazil said.

The confrontation lasted four hours.

According to police, the incident occurred on the bridge connecting the suburb of San Gonzalo with the center of Rio de Janeiro.

The police reported that the attacker spilled gasoline on the bus and threatened to set it on fire. According to officials, the unknown called himself a police officer, but this statement was false.

The unknown didn’t put forward any requirements and, he has “psychological problems,” the representative of traffic police declared.

The operation was carried out by an elite police unit. A sniper was placed nearby. Traffic on the bridge was blocked in both directions, hundreds of cars stuck in traffic.