During Monday's regular press conference, Hong Kong police announced that 31 people, including 17 students, were arrested as a result of violent incidents on Sunday. 

The police expressed concern over the student arrests. "If someone wanted to use these young people to do something illegal and achieve their purposes, it would be despicable," the police said. 

On Sunday, violent protesters gathered in malls in Hong Kong, vandalized shops and attacked people, police added. 

They also announced the arrest of three males for a case of "bomb explosion" in Tuen Mun on Saturday. During the operation, police seized a radio-controlled detonation device, a gas mask and a bulletproof steel plate, etc. 

Police reiterated that they will not tolerate illegal acts and will not allow malls in the city to become lawless areas.