The National Garment Workers Federation (NGWF) led a rally of  Bangladeshi garment workers in Dhaka to demand an increase in the national minimum wage.

The National Garment Workers' Federation (NGWF) led a rally of Bangladeshi garment workers in Dhaka to demand an increase in the national minimum wage.

Garment factories in some parts of Bangladesh have closed for an indefinite period following three days of violent protests by thousands of workers calling for an increase in the national minimum wage.

Local news reports say demonstrations have centred on the Ashulia manufacturing zone near Dhaka, where owners have been forced to shut all 250 garment factories after workers clashed with security forces.

At least 30 people were injured after security officials fired tear gas and rubber bullets to try to break up the crowds.

Labour unrest is also said to have taken place at another apparel hub in Kanchpur where export-oriented factories are located - although the BBC reports that factories in the Export Processing Zone are still working.

Pay and working conditions in factories in Bangladesh have long been a source of concern, with protestors calling for basic pay to be raised to BDT5,000 (US$72) a month to enable workers to meet their living needs including food, shelter, clothes, education, health care and transport.

Currently, most workers earn just BDT1,662 (US$24) per month - the national minimum wage set by the government back in 2006.

But for many, the situation is thought to be even more desperate. Not only have workers had to face rising inflation over the past four years, but factories have cut wages by 20-30% in a bid to compete for orders with countries such as Vietnam, China and India.

And unskilled workers in the garment sector are even worse off, receiving just BDT800 (US$11.5) a month and often forced to work 14-16 hours a day.

Labour groups also claim that in many cases salaries are not paid on time, with delays of up to two months to receive their pay cheques.

Bangladesh has also been criticised for in the most recent annual survey of trade union rights by the International Trade Union Confederation (ITUC).

"The lifting of the state of emergency raised hopes of an improvement in the situation for the Bangladesh trade union movement and better economic conditions for workers, but nothing has changed in practice," the report says.

It adds: "Six garment workers were killed in attacks by the police or company security guards during strikes or protests linked to wage demands."

Officials from the country's Ministry of Labour and Employment and Garment Manufacturers and Exporters Association (BGMEA) in April told just-style they were ironing out a deal to increase worker wages - although no details were given about the scale of the rise or when it would be introduced.

Pressure for change is also coming from global retailers, including Walmart, Gap Inc and H&M, who in February urged the Bangladeshi Prime Minister to take "swift action" over low garment worker wages which they fear could taint their reputations as socially responsible companies.

Garments are Bangladesh's biggest export, with some 4,000 garment factories employing 2m people and accounting for more than 80% of annual export earnings worth $15bn.

But Amin Haque, president of the National Garment Workers' Federation (NGWF), predicts that further labour unrest is inevitable unless the government takes action to raise the national minimum wage to levels that ensure decent standards of living for workers.