BERLIN: Thousands of young people across Europe joined a global day of climate protests on Friday, many wearing masks and keeping their distance against the coronavirus. The rallies marked the resumption of street protests by the "Fridays for Future" movement, which had kept its actions mainly online in recent months because of the pandemic.

Swedish climate activist Greta Thunberg, who launched the school strikes two years ago, led the protest in Stockholm.

The goal was to "build up this pressure on people in power so that something happens", the 17-year-old said outside the Swedish parliament, wearing a white mask emblazoned with the Fridays for Future logo.

With Sweden's coronavirus rules limiting crowd sizes to 50 people, Thunberg said the demonstrations would "focus on being few people in many places and keeping distance."

More than 3,000 rallies were scheduled to take place globally, from Iceland to Australia and both online and in the streets depending on virus restrictions.

Previous global Fridays for Future demos have seen millions of young people pour into cities to demand action against global warming.

In Germany, police said some 10,000 protesters braved the rain to gather at Berlin's Brandenburg Gate. Organisers estimated the figure to be twice as high.

Demonstrators clutched umbrellas and carried signs to highlight the climate crisis, while some scribbled messages on their face masks such as "Not a single degree more" and "Unite behind the science".

A Berlin police spokeswoman said participants were adhering to hygiene regulations imposed to contain the virus spread, with many demonstrators standing or sitting at least 1.5 metres apart.

Elsewhere in Germany, some 7,000 people turned out in the western city of Cologne while the cities of Freiburg and Hamburg each drew around 6,000 demonstrators.

Bad weather across the country however was believed to have dampened the overall turnout somewhat.

A large protest planned in the southern city of Munich had to be cancelled because of a regional spike in coronavirus infections, and was replaced by a smaller event outside the city centre. Climate strike organisers in Austria said that 6,000 people had attended a demonstration in the capital Vienna despite heavy rain and organisational hurdles posed by the Covid-19 pandemic.

Vienna's police department estimated turnout at 2,500.

Protest organisers said that a further 2,000 people had rallied in other parts of Austria using the slogan: "Masks up, emissions down!"