Anti-government protestors in Hong Kong stormed into the Legislative Council building on Monday and painted the walls of the main debating chamber with graffiti, reports said. The protestors also hung a British colonial-era flag on the main podium.

Dozens of demonstrators broke through the glass door of the Legislative Council building, while shouting slogans and spray painting messages on the walls, BBC reported.

A black and white banner hoisted in the debating chamber read in Chinese: “Bow to protect rule of law. Oppose extradition,” reported AFP.

Earlier, the police had held signs warning they would use force if protesters charged the glass exterior walls of the building. They later warned that anyone who breached an internal metal gate would be arrested. According to Reuters, riot police fired pepper spray to disperse the crowd.

Thousands of people in Hong Kong took to the streets on Monday for a rally to mark the 22nd anniversary of Hong Kong’s handover from British to Chinese rule. This was the latest in a series of protests against the extradition bill that could allow people in Hong Kong to be sent to China for trials. The Hong Kong government has agreed to suspend the bill indefinitely, but rallies have continued amid calls for Chief Executive Carrie Lam to resign.

The protests on Monday were mostly peaceful, but a breakaway group of protestors moved to the government building around noon and began ramming the glass door with a metal trolley, but the protestors later dispersed. In the evening, some returned to the Legislative Council building and began pulling off external fencing and entered the building. Protestors then managed to open a gate inside the building and gained access to the chambers.

The Hong Kong police gave an ultimatum to protesters who seized the Legislative Council, warning that they would use “appropriate force” if they are met with resistance while clearing the area, AFP reported.