Daylong demonstrations on Monday in Hong Kong drew hundreds of thousands of people and culminated in heavy damage to the building that houses the territory’s Legislative Council.

Protests that were mostly peaceful were first marred by morning clashes with the police, who used batons and pepper spray against protesters outside a ceremony commemorating the 22nd anniversary of Hong Kong’s return to Chinese control.

Later, the demonstrations again turned destructive when a group of protesters stormed the legislature and worked for hours to move deeper into the building, even while hundreds of thousands of others marched peacefully outside.

One group of protesters used makeshift battering rams to destroy the legislature’s glass windows and doors as they made their way into the building.