HONG KONG, Dec. 16 (Xinhua) -- Hong Kong police said Monday that students accounted for more than half of people arrested during violent incidents that happened on Sunday.

There were 17 students among a total of 31 arrests made on Sunday, Hong Kong police said at a press conference.

Rioters started disruptive activities on Sunday afternoon in areas including Shatin, vandalizing shops and hurling a smoke bomb. Violent acts escalated in Mong Kok at night as rioters blocked roads, attacked police officers with bricks, and set debris ablaze.