Three people have been killed after a long-distance bus in western Norway was hijacked by a man armed with a knife, officials say.

The suspect, a 30-year-old South Sudanese man, was a failed asylum seeker who was about to be deported, police said Tuesday.

The man, who is being treated for knife wounds in hospital, was due to fly to Oslo on Tuesday before leaving the country, police officer Aage Loeseth said.

He was living in a reception centre for asylum seekers in Aardal, a small town in western Norway near the scene of the attack.

The deputy director of the organisation managing the reception centre, Tor Brekke, said the attack had been "completely unexpected".

"There was nothing to indicate any imbalance, or that he could do this," he said.

The suspect was apprehended by fire crews who rushed to the scene after the incident was first reported as a traffic accident on Monday night.

The victims were a 19-year-old woman, the bus driver - both Norwegians-, and a Swedish man. They were the only people on the bus.

"We can confirm that three deceased were on the bus," prosecutor Jorn Lasse Revsnes told broadcaster TV2.

The motive for the attack was not immediately known.

Witnesses said that the man had "acted desperately", according to newspaper VG.

"We first heard it was a traffic accident. But when witnesses approached to help they saw a desperate man inside the bus. He had shown a weapon," emergency official Wenche Hope told VG.

The bus was travelling on the route between the country's second-largest city, Bergen, and the capital, Oslo.

In 2003, on the same route, the driver was killed in another bus hijacking.

Source: Al Jazeera