Thousands of people across Serbia blocked roads in anti-government protests against two new laws, which environmentalists say will let foreign companies exploit local resources.

The protests are directed against the ruling Peoples' Progressive Party, led by President Aleksandar Vucic, with next year being an election year where both parliamentary and presidential elections will take place.

Serbia's government will allow companies including Rio Tinto, an Anglo-Australian lithium miner, and China's Zijin, a copper miner, to exploit local resources. Environmentalists say these projects will pollute Serbia's land and water.

Thousands also gathered on the main bridge in the Serbian capital of Belgrade, chanting "Rio Tinto go away from the Drina River," holding banners reading "Stop investors, save the nature."

Roadblocks were also set up across Serbia, including Novi Sad, Sabac, Uzice, Nis, and Zajecar.

Rio Tinto claimed it will adhere to domestic and EU environmental standards, however green activists assert that the $2.4 billion lithium mine will irreversably pollute the area's drinking water.

President Aleksandar Vucic published a picture on his Instagram profile from the village of Gornje Nedeljice where Rio Tinto has already started buying land for its future lithium project.

He said that he would later call a referendum to allow people to decide whether the project should go through.

"Everything we build today we are leaving to our children," Vucic wrote on Instagram.