About 1,000 Czechs belonging to labor unions and non-governmental groups are marching through the Czech capital to protest government reforms and austerity cuts.
The march Tuesday is the latest in a series of rallies in a "stop the government" campaign that is urging the center-right Cabinet to abandon austerity measures and resign.
Union leaders said they also plan to blockade five ministries in the following weeks and have been threatening a nation-wide strike.
The government says the cuts and reforms are needed to keep the budget deficit low.
About 100,000 people rallied in Prague April 21 over the same issue in one of the biggest demonstrations since the fall of communism.
Farmers also plan to blockade roads across the country Wednesday to protest cuts in diesel subsidies.