Police kill four at Bangladesh power plant

At least four people have been shot dead and many injured as police opened fire at workers demanding a pay rise at a Chinese-backed coal-fired power plant in southeastern Bangladesh.

Police were forced to open fire when protesters attacked them on Saturday at the under-construction power plant in Chittagong, local police official Azizul Islam told Reuters.

"Four died and many injured ... We're trying to control the situation," Islam said, adding that at least six police personnel were among the injured.

The $US2.4 billion ($A3.1 billion) power plant, located 265km southeast of the capital Dhaka, is a major source of foreign investment into Bangladesh, and one of a series of projects Beijing is pushing to cultivate closer ties with Dhaka.

In 2016, China's SEPCOIII Electric Power Construction signed a deal with S Alam Group, a Bangladeshi conglomerate responsible for building construction at the site.

That year, four demonstrators opposing its construction were killed after villagers for and against the power plant clashed before riot police opened fire after coming under attack.