Tens of thousands took to the streets in cities across Europe and Australia Saturday as anger mounted over fresh Covid restrictions imposed against a resurgent pandemic.

And Dutch police faced a second night of rioting -- this time in The Hague -- after the previous night's violence in the port city of Rotterdam.

Clashes erupted after a day of mainly peaceful protests elsewhere in the Netherlands, with rioters throwing stones and fireworks at police and setting fire to bicycles. Several people were arrested.

Europe is battling a fresh wave of infections and several countries have tightened curbs, with Austria on Friday announcing a nationwide partial lockdown -- the most dramatic restrictions in Western Europe for months.

The Netherlands went back into partial lockdown last Saturday with at least three weeks of curbs, and is now planning to ban unvaccinated people from entering some venues, the so-called 2G option.

Several thousand protesters angry at the latest measures gathered in Amsterdam. Another thousand marched through the southern city of Breda near the Belgian border, carrying banners with slogans such as "No Lockdown".

Organisers said they opposed Prime Minister Mark Rutte's plans to exclude the unvaccinated from bars and restaurants.

"People want to live, that's why we're here," said organiser Joost Eras.

But "we're not rioters. We come in peace," he said, distancing himself from the chaos the previous night in Rotterdam, in which police said they had fired both warning and targeted shots and used water cannon.

In Austria, around 40,000 came out to protest in central Vienna near the Chancellery, responding to a call from the far-right FPO party.

They held up banners decrying "Corona dictatorship" and slamming the "division of society".

"It's not normal that the government deprives us of our rights," said 42-year-old teacher Katarina Gierscher, who travelled for six hours to attend the rally.

- Yellow star stunt -

Some protesters wore a yellow star reading the words "not vaccinated", a nod to the Star of David many Jews were forced to wear during the Nazi era.

Austria's Interior Minister Karl Nehammer expressed his outrage, saying in a statement that it "insults the millions of victims of the Nazi dictatorship and their families".

From Monday, 8.9 million Austrians will not be allowed to leave home except to go to work, shop for essentials and exercise. The restrictions will initially last 20 days with an evaluation after 10 days.

Vaccination against Covid-19 in the Alpine nation will be mandatory from February 1 next year.

Thousands also marched in Croatia's capital Zagreb and in Denmark, around a thousand people protested against government plans to reinstate a Covid pass for civil servants going to work. 

"Freedom for Denmark," cried some of the marchers at a rally in Copenhagen organised by the radical Men in Black group, who believe Covid-19 is just a "scam".

- French skiers 'delighted' -

In Australia around 10,000 marched in Sydney and there were also protests in other major cities against vaccine mandates applied to certain occupations by state authorities.

"In Australia where a fanatical cult runs our health bureaucracies, they say it's OK" to vaccinate children, right-wing politician Craig Kelly told the Sydney crowd to large cheers.

On Saturday, France dispatched dozens of elite forces to its Caribbean island of Guadeloupe after arson and looting overnight in the overseas territory, despite a newly imposed night curfew.

In Iran, the health ministry said Saturday more than half of the population had been fully vaccinated against Covid-19, as infection and death rates in the country have started to drop.

Winter sports have again been hit by the pandemic. Germany has ordered next month's Ski Jumping World Cup in Klingenthal to be held behind closed doors.

But it wasn't all bad.

In France, jubilant skiers hit the slopes as resorts fully opened their doors for the first time in almost two years.

"We're delighted to be able to get the lifts up and running again and to be able to do our job 100 percent," rescue worker Emmanuel Laissus told AFP in the Val Thorens resort in the southeast.