Thousands of Czechs demonstrated in Prague's central square on Sunday, calling on the government to quit as they protested over high inflation and energy prices.
Police did not give estimates of the size of the protest, named "Czechia against poverty".
The protest, like a similar demonstration in March, was organised by non-parliamentary political party PRO, which has criticised the centre-right government of Prime Minister Petr Fiala for its handling of the energy crisis that has hit Europe since Russia's invasion of Ukraine more than a year ago.
PRO has also blasted the government for hurting freedom of speech as part of efforts to counter disinformation, and has called on it to push for peace in the Ukraine war, while denying being a pro-Russian party.
"Collect the last remnants of your honour, realize that you are not up to the job, and resign," protest organiser and PRO leader Jindrich Rajchl told the crowd which filled half of Prague's Wenceslas Square, according to news website iDNES.cz.
The protest was due to march to the government office.
The Czech Republic, like other countries in Europe, has been hit by rising inflation that has soared into double digits in the past year and high energy prices that are cutting into household budgets.
While Fiala has sought to ease the burden on families and firms, it has also sought to rein in high budget deficits and drew smaller protests recently for slowing an inflation-linked rise in state pensions.
Recent polling from Kantar for Czech TV saw support for the five-party government slipping, with the main opposition party, ANO of former prime minister Andrej Babis, extending its lead over Fiala's party to 29% compared with 20%.
