Thousands of protesters defied authorities and gathered in the Dutch capital Amsterdam on Sunday to oppose coronavirus restrictions, leading to clashes and 30 arrests.
"This is Holland! Power to the people!" chanted one protester.
The demonstrators rallied in one of the city's main squares, despite Dutch authorities banning the protest beforehand.
Police said anti-riot officers had to use force after protesters refused to leave the square despite a warning.
Four officers were injured in the clashes with protesters and 30 arrests were made for offences including assault, public disorder, possession of a forbidden weapon and not respecting security forces, they added.
Local media reported that at least two protesters suffered injuries.
Prime Minister Mark Rutte announced a lockdown on December 18, one week before Christmas, in response to a fresh wave of Covid infections fuelled by the Omicron variant.
Non-essential shops, restaurants, bars, cinemas, theatres and museums will remain closed until January 14 and schools until January 9.
Under the new rules, only two people may meet outdoors, with an exception for burials, but no travel restrictions were imposed.