Bangladesh garment factories have fired hundreds of workers since protests in October demanding higher wages, three labour unions representing half a million workers told Reuters this week, while many others are on the run fearing arrest.

Clashes during the protests killed four workers and injured dozens of others, with the police filing cases against hundreds of unidentified people for vandalism.

The government agreed in November to raise minimum wages by more than 56% to 12,500 taka ($114) a month, which many workers have still called too low. Bangladesh has become the world's second-biggest garment exporter after China partly thanks to low wages.

The three unions - Bangladesh Garments and Industrial Workers Federation, National Garment Workers Federation and Bangladesh Garments Workers Unity Council - estimated that 1,000 to 5,000 workers had either been fired in the last two months or had gone into hiding.

But Faruque Hassan, president of the Bangladesh Garment Manufacturers and Exporters Association, said he was not aware of any retrenchments, adding that the industry body would act if "any such incidents are brought to our notice".