Thousands of workers at Bangladesh's main Chittagong port have taken strike action over a US company's plan to set up a rival dock.

Chittagong Port Authority officials said the four-hour stoppage closed the port, which disrupted loading and unloading of about 20 ships.

Twenty-two unions warned they would take indefinite strike action if the Stevedoring Services of America (SSA) was allowed to set up a rival $550m container terminal.

"We will go for a bigger protest unless the government cancels its plan," said Mahfuzur Rahman, a spokesman for the unions.

The government has said it would give SSA the go-ahead to build the country's first private container terminal to help ease congestion and encourage direct foreign investment.

Jobs 'at risk'

The labour unions claim the proposed terminal would take away their jobs and siphon customers from the state-run port, a claim SSA has repeatedly denied.

On Tuesday about 6,000 workers held a peaceful protest that shut down the port.

SSA has been trying to set up the new dock for several years, but has failed due to resistance from port workers and Chittagong's mayor.

The company is the largest terminal operator in the US and has a presence in over 150 locations worldwide including Chittagong and also Kakinada and Dhamra in neighbouring India.

Chittagong on the Bay of Bengal is 216 kilometres southeast of the capital, Dhaka.

Privatisation plans

The government announced at the start of April plans to privatise twenty-one state-owned companies in the jute, textile, paper and oil sectors.

It admitted the privatisations would result in the loss of 30,000 public sector jobs.

The plan forms part of the government's measures to assure international financial organisations of the sincerity of its economic reforms and to attract more development assistance.