Police fired warning shots, injuring an unknown number of people, as riots broke out on Friday night in downtown Rotterdam at a demonstration against plans by the Dutch government to restrict access for unvaccinated people to some venues.
In a tweet, police said that "there are injuries in connection with the shots" during the violent unrest.
Riot police used a water cannon in an attempt to drive hundreds of rioters from a central street in the port city.
Several lit fires, flares and fireworks were also seen during the demonstration.
The protest forced authorities to close the city's main railway station.
In the lead up to the demonstration, the government has said it wants to introduce a law that would allow businesses to restrict the country's coronavirus pass system to only people who are fully vaccinated or have recovered from COVID-19.
That proposal would exclude people who test negative.
The country has seen a string of record numbers of coronavirus infections in recent days and a new partial lockdown came into force a week ago.
In January, rioting broke out in Rotterdam and other Dutch cities after the government announced a curfew in an attempt to rein in soaring coronavirus infections.
Earlier on Friday, the government banned fireworks on December 31 for the second straight year.
The ban is intended "to prevent, as much as possible, extra strain on health care, law enforcement and first responders," the government has said.