THOUSANDS of Bangladeshi garment workers churning out clothes for top global brands went on strike on January 13 and clashed with police as protests over low wages entered a second week.

Police said water cannons and tear gas were fired to disperse huge crowds of striking factory workers in Savar, a garment hub just outside the capital Dhaka.

So far 52 factories, including some big ones, have shut down operations due to the protests.

One worker was killed on January 8 and 50 others injured, after police fired rubber bullets and tear gas at some 5,000 protesting workers.

Bangladesh is dependent on garments stitched by millions of low-paid tailors on factory floors across the emerging South Asia economy of 165 million people. Roughly 80 per cent of its export earnings come from clothing sales abroad, with global retailers H&M, Primark, Walmart, Tesco and Aldi among the main buyers. Bangladesh's 4,500 textile and clothing factories shipped more than US$30 billion worth of apparel last year.

Minimum wages for the lowest-paid garment workers rose by a little over 50 per cent this month to 8,000 taka (S$129) per month. But mid-tier tailors say their rise was paltry and fails to reflect the rising costs of living, especially in housing.

"The wages were hiked after five years. But in the five years, the cost of living has increased more than the wage hike," Mr Babul Akhter, head of the Bangladesh Garment and Industrial Workers Federation, said.

The Bangladesh Garment Manufacturers and Exporters' Association, which wields huge political influence, warned all factories might be shut if tailors do not return to work immediately.

Last year Bangladesh was the second-largest global apparel exporter after China. It has ambitious plans to expand the sector into a US$50 billion a year industry by 2023.

But despite their role in transforming the impoverished nation into a major manufacturing hub, garment workers remain some of the lowest paid in the world.

The industry also has a poor workplace safety record. The Rana Plaza garment factory collapse in 2013 killed more than 1,130 people in one of the world's worst industrial accidents.

Bangladeshi police on January 9 used water cannon to disperse 10,000 striking garment workers who were blocking a major highway in a fourth day of industrial action, an official said.

Police said about 10,000 workers blocked the highway at several places outside the industrial town of Savar, on the outskirts of Dhaka, for hours after some 50,000 workers walked out of their factories in the morning demanding higher wages.

Some 2,000 workers from a major factory in Dhaka also walked off their shift and blocked a road in the northern suburb of Kalshi.

The protests are the first major test for Prime Minister Sheikh Hasina since winning a fourth term in December 30 elections marred by violence, thousands of arrests and allegations of vote rigging and intimidation.

"We won't leave the road until our demand is met," said Ms Asma Khatun, a protesting worker at Kalshi.

Mr Mohammad Abdullah, another worker, said manufacturers have hired local musclemen to stop workers in other factories from joining the protest.

The online edition of the Manabjamin newspaper said at least 50 protesters were injured in waves of clashes, which also spread to garment factory hubs in Dhaka.