France’s tobacconists are protesting against plans to force cigarette companies to use plain, unbranded packaging by disabling traffic speed cameras.

The radar “hooding” – by covering them with bin liners – is symbolic: a “cover up” that deprives the government of money in the same way that the anti-smoking legislation will reduce tobacco sales and tax revenue, the protesters say.

The first hooding took place over a month ago and, by this week, speed trap cameras in as many as 20 of 97 districts had been affected, said the group representing France’s tabac bars, the Buralistes Confederation.

“It’s a sign that anger is mounting,” a spokesman said.

BFM TV showed a group of tobacconists wearing white masks on a night-time radar-hooding expedition.

The spokesman said three activists had been arrested this week, but that all were released without charge.

On Wednesday, a protest march is planned in Paris. A tabac shop on the march route will be stocked with plain packaged cigarettes.

Many of the tabac outlets, with their distinctive red cigar-shaped signs, are also bars and cafes. Some sell stamps and newspapers, too, but they point out that a key function on their monopoly on tobacco sales is collecting tobacco tax: 14bn euros ($15bn) for the French Treasury every year, the confederation said.

France is one of four EU countries that plan to follow Australia’s example and impose plain cigarette packaging in May next year.

A European Union law passed last year mandated that health warnings cover 65% of the front and back of cigarette packs, and 50% of the sides.

The remaining space is available for branding, but the law allows member states to impose plain packaging rules when “justified on grounds of public health, are proportionate and do not lead to hidden barriers to trade between member states”.

Philip Morris International and British American Tobacco have sued the British government over its plan to require plain packaging, arguing that it would rob them of their intellectual property and restrict trade.