STAVANGER, Norway — A knife-wielding man today hijacked a bus in western Norway and killed three people on board, including the bus driver, police said.

The suspect, described as a man in his 50s, was arrested after the attack in Sogn and Fjordane county, local police said.

Authorities first got reports of injuries in connection with a bus accident and rescuers from the fire department were the first to arrive on the scene, police spokesman Odd Arne Solvag said. He said the rescuers apprehended the suspect who was later arrested by police.

Solvag said the suspect was not an ethnic Norwegian but could not give details on where he was from.

The motive was not immediately clear.

Oslo police was getting ready to send an anti-terror unit to the scene aboard army helicopters but called off the deployment after receiving reports that the suspect had been arrested.