A massive protest in Serbia against a lithium-mining project prompted President Aleksandar Vučić to call a government crisis meeting in the early hours of Sunday.

Tens of thousands of protesters marched through the capital of Belgrade on Saturday to demonstrate against the opening of what could become one of the largest lithium mines in Europe. Industry is keen to secure supplies of the crucial raw material for electric-car batteries.

Around 30,000 marchers took to the streets to protest against the opening of a lithium mine by the Australian-British mining consortium Rio Tinto. Environmental activists fear the project will pollute land and water in Serbia's western Jadar region, where the deposit is located.

Demonstrators have organized nearly 50 protests since June in an effort to persuade the Serbian government to halt the project and to ban geological exploitation.

Saturday's protest ended with the blockage of two train stations, and Serbian authorities said it breached the law. Government officials labeled the actions politically motivated and said they were an effort to bring down the president and the government, Reuters reported.

Vučić claimed on Friday to be informed by Russian security services that “a coup d’état” against him was being prepared, Bulgarian media reported.

Lithium is used in electric car batteries and has become increasingly coveted in automotive supply chain reorganization.

The Rio Tinto project has been officially backed by the European Union. German Chancellor Olaf Scholz and European Commission Vice President Maroš Šefčovič signed deals last month granting EU car makers such as Germany’s Mercedes-Benz and French-Italian automaker Stellantis exclusive access to Serbian lithium.