DHAKA: About 50,000 garment industry workers held their largest protest so far in the Bangladeshi capital of Dhaka to demand an increase of more than 1-1/2 times in the minimum wage, police and labour officials said yesterday.

"Our backs are against the wall, so we don't have any alternative unless we raise our voice strongly," Nazma Akter, president of the United Garments Workers' Federation, which groups 52 garment worker's groups, told the peaceful protest.

Bangladesh's $20-billion garment export industry employs roughly four million workers who earn about 3,000 taka ($38) a month, or half what Cambodian factory workers now earn. They want a raise to 8,000 taka ($103) per month.

Although the factory owners earlier agreed to a raise of just 20 per cent, the workers refused this, calling it "inhuman and humiliating".

"It is the largest gathering of its kind to realise their demand for raising wages," said Dhaka Metropolitan Police Chief Habibur Rahman.

Earlier more than 300 factories in an industrial zone near the capital shut production as workers came out in support of the same demand, blocked a highway and damaged several vehicles.

The government is in talks with labour groups and factory owners on a new minimum wage. Bangladesh last hiked its minimum garment-worker pay in late 2010, almost doubling the lowest pay.

This time, wages are unlikely to go much higher as factory owners say they cannot afford higher salaries as Western retailers are used to buying cheap clothing.

In July, Bangladesh approved a labour law to boost worker rights, following the April collapse of a factory building that killed 1,132 garment workers.

Bangladesh faced pressure to adopt better labour laws after the European Union, which gives preferential access to the country's garment industry, threatened punitive measures if it did not improve worker safety standards.