At least five people were killed and dozens injured in Bangladesh on Saturday after police opened fire on a crowd of workers protesting to demand unpaid wages and a pay rise at a Chinese-backed power plant, officials and police said.

Police opened fire after about 2,000 of the protesters began hurling bricks and stones at officers at the construction site of the coal-fired plant in the southeastern city of Chittagong, local police official Azizul Islam told Reuters.

Four protesters died at the scene and another died in hospital, he said. “We’re trying to control the situation,” Islam said, adding that at least six police officers were among those injured.

The workers attacked and set fire to several structures at the 1,320-MW power plant, located 265km southeast of Dhaka, he added. Local government official Saiduzzaman Chowdhury said the workers were protesting over unpaid wages.