Police have fired rubber bullets and tear gas to disperse thousands of garment workers who rampaged through industrial towns in Bangladesh to protest the killing of two factory workers during a demonstration for higher wages.

Police official Mohammad Nazrul Islam says at least 30 people were injured in Tuesday's violence.

The two factory workers died earlier Tuesday, a day after they were seriously wounded by rubber bullets fired by police outside the capital, Dhaka.

Garment workers have been protesting for more than a month to press for a wage hike.

Workers in Bangladesh are poorly paid and are forced to work in poor and unsafe working conditions in an industry that earns up to $20 billion a year — about 70 percent of the country's export earnings.