At least 200 white collar workers gathered outside Montreal City Hall Monday evening to put pressure on city officials to negotiate a collective agreement.

The crowd was noisy, with protesters blowing horns and blasting loud music that included clips of Montreal Mayor Denis Coderre blaring through speakers.

Security was beefed up, with police officers at every door of the building.

“There’s a bit of nervousness here. Back in August, there was a large, violent protest at City Hall and there are fears that could happen again,” said CBC Montreal reporter Tanya Birkbeck who was live at the scene.

Last summer, municipal workers who were protesting — mostly firefighters — stormed city hall and ransacked the council chamber.

Some were charged with assault, unlawful assembly and mischief. Six firefighters were fired.

Some firefighters attended Monday’s rally to show support for the white collar workers, who have been without a collective agreement for the last three years.