DHAKA, Bangladesh -- Police said they fired rubber bullets and tear gas Tuesday 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.

At least 30 people were injured in the violence, said police official Mohammad Nazrul Islam.

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 in Bangladesh have been protesting since last month to press for a wage hike.

In the latest violence, security forces fired rubber bullets and tear gas to stop angry workers from vandalizing factories, Islam said.

The workers also set up roadblocks with burned tires and abandoned vehicles, disrupting traffic in the industrial towns of Gazipur and Ashulia, outside of Dhaka.

A protest leader, Delwar Hossain, said the workers were demonstrating peacefully and were attacked by police "without provocation."

Since the protests began in October, the government has deployed paramilitary border guards to boost security in Gazipur, a hub of several hundred garment factories.

Police said about 50 garment factories shut down for the day Tuesday because of the protests.

Garment workers in Bangladesh are poorly paid and are forced to work under poor and unsafe conditions in an industry that earns up to $20 billion a year -- about 70 per cent of the country's export earnings.