Thousands of demonstrators brought the centre of Prague to a standstill on Monday night in a display of anger over the appointment of a communist-era riot squad officer to head the Czech parliament’s police watchdog. Chanting “communists are murderers” and “we have had enough”, protesters held sheets of paper rolled up to resemble police batons in an expression of indignation over the installation of Zdeněk Ondráček, a Czech Communist party MP, as chair of the parliament’s general inspection of security forces commission.