HONG KONG (AP) — Hong Kong police on Monday accused activists in the long-running pro-democracy movement of inciting minors to commit crimes.

The claim Monday comes two days before a planned New Year’s Day march that is expected to attract tens of thousands of participants.

Chief police spokesman Kwok Ka-chuen told reporters that the force was in close contact with the organizers of the Jan. 1 event, but would not tolerate threats to public safety.

Kwok also said young people had been motivated to commit criminal acts during the protests, including dropping objects from the upper stories of apartment buildings. It wasn’t clear whether those actions were directly tied to any specific demonstration.

“Over the weekend, during our arrest operation, we arrested a large number of youngsters and are very alarmed that some criminals incite youngsters to commit crimes,” Kwok said, adding that some of the violence had been inspired by the children’s teachers.

Children as young as 12 have been among the nearly 7,000 people arrested during the protests, which have drawn broad support and were originally sparked by now-discarded legislation that would have allowed citizens of the semi-autonomous Chinese city to be sent to China for trial.

The movement started in opposition to a now-shelved proposed law that would have allowed suspects in Hong Kong to be sent to mainland China to stand trial. Protesters’ demands have since expanded to include universal suffrage and an investigation into alleged police abuses, and have frequently broken out into pitched battles between the two sides.