Thousands of people in Serbia have protested in Belgrade against plans to mine one of Europe's largest deposits of lithium - a crucial raw material for electric car batteries.
Activists say the mine would cause irreversible environmental destruction to Serbia's Jadar Valley, where the deposit is located.
A licence granted to mining giant Rio Tinto was revoked in 2022 following widespread protests in the country, but the project was restarted last month following a court decision and government U-turn.
President Aleksandar Vucic has insisted that strict environmental safety protocols will be put in place.
Protesters in the capital chanted "Rio Tinto get out of Serbia" and held banners saying "We do not give Serbia away" as they marched through the city.
Serbia's Interior Ministry estimated that between 24,000 and 27,000 people joined the protest.
Environmental activists also took over two of the city's main railway stations - with some lying or sitting on the tracks.
Interior Minister Ivica Dacic said in a statement that organisers were "warned" by police that their actions "were not in accordance with the law".
He vowed charges would be filed against "all perpetrators".
Activists want legislators to permanently ban the mining of lithium and boron in Serbia, warning of possible dangers to public health and contamination of land and water.
They had given the government a deadline of Saturday to implement the ban.
Last month, Serbia restored Anglo-Australian mining company Rio Tinto’s licence to extract the mineral in the Jadar Valley in the west of the country.
Serbia's government said the previous decision to block the project in 2022 was "not in line with the constitution and the law".
The EU hailed it as a “historic day for Serbia, as well as for Europe”.
Speaking about the revived Rio Tinto project, Green-Left Movement co-leader Biljana Djordjevic said that activists "fear Serbia will be sacrificed to provide lithium for electric vehicles that pretty much nobody in Serbia can afford".
Carmakers will need ever more lithium for batteries, as the transition to zero-emission vehicles accelerates – and Rio Tinto’s $2.4bn (£1.8bn) Jadar Valley project could provide as much as nine-tenths of Europe’s current lithium needs, and turn the company into one of the world's leading lithium producers.
