French police officers are protesting what they call increasingly unsafe working conditions, after an officer was critically wounded by a convict who had not returned from a prison furlough.

A few thousand officers gathered Wednesday on the Place Vendome in Paris, waving union flags and sending up orange smoke from flares. The crowd fell silent as an announcer addressed the justice minister in the name of their injured comrade.

The shooting hit a nerve among officers feeling strained after a particularly tense and high-security year in France, which started with deadly extremist attacks on the satirical newspaper Charlie Hebdo and a kosher market.

Similar protests are planned around France. The prime minister planned to address their concerns later Wednesday and President Francois Hollande promised to meet police unions next week.