Russia ? Riot police clubbed, kicked and detained dozens in the Pacific port of Vladivostok on Sunday in a harsh crackdown on a protest that was one of dozens across Russia by people outraged over an increase in car import tariffs.

With unemployment spiking, prices rising and the ruble sliding, the protests over a seemingly mundane tariff appear to be broadening into a wide expression of public discontent — and a genuine challenge to the Kremlin.

The government announced the tariffs on imported automobiles earlier this month to bolster flagging domestic car production and try to head off layoffs or labor unrest among the country’s more than 1.5 million car industry workers.

But imported used cars are highly popular among Russians, particularly throughout the Far East.