The Netherlands was hit by a second wave of riots on Monday evening after protesters again went on the rampage in several cities following the introduction of a coronavirus curfew over the weekend.
Riot police clashed with groups of protesters in Amsterdam as well as the port city of Rotterdam, Amersfoort in the east, and the small southern city of Geleen near Maastricht, police and Dutch news reports said.
Amsterdam police said they had made eight arrests.
"At the moment there's a confrontation between police, riot police and rioting youths who are throwing fireworks," Geleen police said in a tweet.
"One person has been arrested," police added.
In Rotterdam, police used a water cannon after clashing with rioters, the national newscaster NOS reported.
The city's mayor Ahmed Aboutaleb has issued an emergency decree which gives police broader powers of arrest.
"The riot police have carried out charges and arrests have been made," Rotterdam's city council said in a tweet.
"There is an urgent request to all to leave the area," the council added.
Earlier, Prime Minister Mark Rutte condemned "criminal violence" which broke out Sunday, prompting what police officials described as the "worst rioting in 40 years".
Police arrested around 250 people after using water cannon and tear gas during demonstrations in Amsterdam, Eindhoven and other towns on Sunday, local media said.
Late Monday, mayors in several Dutch cities announced they will introduce emergency measures to try and prevent further rioting.
On Sunday rioters looted shops, burned cars and torched a coronavirus testing station after the country's first curfew since World War II took effect late Saturday.
"It's unacceptable. All normal people will regard this with horror," Rutte told reporters.
"What motivated these people has nothing to do with protesting, it's criminal violence and we will treat it as such."
Amsterdam police used dogs against protesters who gathered Saturday near the famed Van Gogh museum.
In a larger protest in the southern city of Eindhoven, police fired tear gas to disperse a crowd of several hundred.
Businesses were looted at Eindhoven's central train station, where a car was torched.
Eindhoven mayor John Jorritsma likened the situation to "civil war" and called for the army to be sent in.
Rutte condemned the "idiots" who pelted a hospital in the town of Enschede with stones.
Unrest started on Sunday
Unrest had also erupted Saturday in The Hague, Breda, Arnhem, Tilburg, Appeldoorn, Venlo and Roermond.
A Covid-19 testing centre was set on fire in the village of Urk in the staunchly Protestant "Bible Belt" which runs through the central and northern Netherlands.
Police also arrested a 39-year-old man in the central city of Almere on Saturday for posting an online message threatening journalists, national news agency ANP reported.
Violators of the 9 pm to 4:30 am curfew, which is set to last until at least February 10, face a €95 fine.
Exemptions are allowed, for example for people having to work, attend funerals or walk their dogs, on condition that they present a certificate.
The Netherlands was already under its toughest measures since the start of the pandemic, with bars and restaurants having closed in October, and schools and non-essential shops shut since December.
Parliament approved the curfew last week, after insisting it should start half an hour later than originally planned, despite criticism from some lawmakers.
Police Union chief Koen Simmers on Monday told the NOS current affairs programme Nieuwsuur that police were prepared should the rioting continue.
"I hope it was a one-off, but I'm afraid it could be a harbinger for the days and weeks to come," Simmers said.