Twelve people have been arrested, including 11 men and one woman, after they participated in protests on Monday, the Hong Kong police announced.

The suspects, aged between 14 and 36, are accused of charges including unlawful assembly, assaulting a police officer, obstructing a police officer, possession of offensive weapons, contravening the Air Navigation (Hong Kong) Order 1995 and failing to carry identity documents.

Police also arrested a man who participated in both the demonstrations at the Legislative Council on July 1 and the protests at the police headquarters on June 21. The 31-year-old suspect surnamed Poon has been accused of criminal damage, assaulting a police officer, forcible entry and behaving in a disorderly manner in a public place.

Nine Hongkongers have also been arrested for Internet-related crimes, including cyberbullying and circulating the personal data of police officers.

Hong Kong police said it received over 800 reports from officers saying that their private information including names, phone number, and home address have been published on social media platforms following clashes between police and protesters in previous protests. 150 of these cases have been passed to the privacy commissioner’s office for further investigation.

The suspects, who are aged from 16 to 40, were arrested on Tuesday for accessing computers with dishonest intent, disclosing personal information without approval, criminal destruction and threats of criminal destruction.

One of them was believed to be responsible for an unsuccessful distributed denial-of-service (DDoS) attack on the police force’s website. Local journalists were given a 90-minute tour to survey the damage sustained by the Legislative Council (LegCo) building. They found graffiti on the walls, tables overturned, the city’s emblem defaced, and portraits of former LegCo presidents removed. According to a lawmaker who represents the insurance industry, the damage could amount to a total of HK$10 million ($1.3 million).