At least 16 people have died after a huge fire broke out at a garment factory in Bangladesh, with officials warning that the toll could rise.

Sixteen bodies have been recovered and would be handed to families after DNA testing, as they have been burnt beyond recognition, the fire service said.

Distraught relatives gathered outside the four-storey factory in Dhaka's Mirpur area on Tuesday in search of their loved ones still missing.

The blaze, which broke out at the factory around midday, was extinguished after three hours. But an adjacent chemical warehouse continued to burn, authorities said.

Large fires are relatively common in densely populated Bangladesh, often due to lax safety standards and poor infrastructure. Hundreds of people have been killed in fires in recent years.

Fire service officials have not determined which of the two buildings caught fire first. Eyewitnesses reported that the warehouse stored bleaching powder, plastic, and hydrogen peroxide, materials that could intensify fires. Plastic also releases toxic fumes when burned.

Most of the deaths were attributed to toxic gas exposure and the locked roof door of the building, the fire service noted. Fire service director Mohammad Tajul Islam Chowdhury stated that the victims likely died 'instantly' from inhaling 'highly toxic gas.'

Authorities are working to locate the owners of the factory and warehouse while investigating the legality of the warehouse's operations. Reports indicate that the chemical warehouse lacked the necessary fire safety clearances.

Tearful family members stood outside the charred buildings, many of them clutching photographs of their missing relatives. A devastated father searching for his daughter expressed the agony of not knowing her fate.

Bangladesh has a troubling history of industrial disasters, with incidents in 2021 and 2019 leading to numerous deaths due to poor safety measures. The Rana Plaza collapse in 2013 remains the deadliest industrial accident in the nation, claiming more than 1,100 lives.