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 but were burned 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 ascertained which of the two buildings caught fire first. According to eyewitnesses, the chemical warehouse stored bleaching powder, plastic and hydrogen peroxide, all of which can intensify fires. Plastic also releases toxic fumes when burned.

Fire service director Mohammad Tajul Islam Chowdhury told local media the victims probably died instantly after inhaling highly toxic gas. An investigation on whether the warehouse was operating legally is ongoing.

Tearful family members stood outside the charred buildings, many of them clutching photographs of their missing relatives. Among them is a man searching desperately for his daughter, Farzana Akhter. When I heard about the fire, I came running. But I still haven't found her....I just want my daughter back, he told Reuters news agency.

Recent deadly incidents, including a 2021 fire at a food and drink factory that left at least 52 dead, highlight the ongoing safety challenges in Bangladesh's industrial sector.