BBC News:- About 100,000 people marched in Glasgow to demand more action on the climate crisis, organisers have said.
The protest was the biggest so far during the COP26 summit and took place alongside hundreds of similar events around the world.
Greta Thunberg joined the march but did not speak, leaving activists such as Vanessa Nakate to address a rally.
Police arrested 21 scientists who chained themselves together and blocked a road bridge over the River Clyde.
Officers also contained a group of socialist activists after pyrotechnics were set off during the march – one person was then arrested.
However the force said the day passed “largely without incident”.
The “Global Day of Action for Climate Justice” march started at Kelvingrove Park in the west of the city and Queen’s Park in the south at about midday and made its way along a pre-agreed three-mile route to Glasgow Green.
About 100 climate change demonstrations were held in other parts of the UK while events were also taking place in a further 100 countries including Kenya, Turkey, France, Brazil, Australia and Canada.
In London, protesters marched from the Bank of England to Trafalgar Square while another large demonstration happened in Cardiff.
The opening speeches at the protest rally at Glasgow Green came from representatives of indigenous people around the globe.
Ugandan activist Vanessa Nakate later told protesters: “The climate and ecological crises are already here. But so are citizens from around the globe.
“Leaders rarely have the courage to lead. It takes citizens, people like you and me, to rise up and demand action. And when we do that in great enough numbers, our leaders will move.”
It was understood that Greta Thunberg decided to give space to other speakers as she had already addressed youth activists in a march and rally on Friday.