Police arrested five males who had gathered in Tokyo's Shibuya Ward on Thursday night to ring in the New Year on suspicion of assaulting riot officers after they jumped on the roof of a police vehicle.

The five, two teens and three in their 20s, allegedly obstructed officers from performing their duties around midnight Thursday.

Crowds of young people had gathered at the scramble crossing outside Shibuya Station late Thursday night and into early Friday morning to celebrate the New Year. About 1,000 police officers were mobilized in the area.

In Nagasaki, the body of a 20-year-old man was found early Friday after he had jumped into a river, police said. Yudai Nakamura, who was on his way to a shrine with his friends to celebrate the New Year, was intoxicated when he jumped from a bridge into the river.