POLICE IN BANGLADESH have arrested eight people on murder charges in connection with a factory fire that killed at least 52 people, many of whom were trapped inside by an illegally locked door.

The blaze began at the five-storey Hashem Foods factory in Rupganj, just outside the capital Dhaka, on Thursday night, sending huge clouds of black smoke billowing into the sky.

Police discovered dozens of bodies on Friday afternoon after the fire was extinguished.

Jayedul Alam, police superintendent for Narayanganj district, said the eight people arrested are in custody.

Bangladesh’s home minister Asaduzzman Khan said among those detained is the chairman and managing director of Sajeeb Group, which owns the factory.

Visiting the factory site on Saturday, Mr Khan described what had happened as “murder”, and said those responsible will be punished.

Bangladesh has a tragic history of industrial disasters, including factories catching fire with the workers locked inside.

In similar cases, owners have faced culpable homicide charges for their negligence.

Officials say the main exit of the factory that caught fire on Thursday was locked from the inside, and many of those who died were trapped.

One of them was 23-year-old Rima Akter, who made desperate calls to her family as the fire began to engulf the factory.

On Saturday, her mother and other family members struggled to identify her remains in the morgue at the Dhaka Medical College Hospital.

“We have checked 36 body bags, but it is very difficult to identify her,” her brother-in-law Arafat Rahman said.

Her mother cried as officials tried to reassure several families waiting outside the hospital that the bodies would be returned once DNA tests have been carried out, as most had suffered severe burns.

Forensic experts collected DNA samples from victims’ family members, and by late Saturday afternoon samples from 33 of the deceased had been collected, officials at the hospital said.

The factory is a subsidiary of Sajeeb Group, a Bangladeshi company that produces juice under Pakistan’s Lahore-based Shezan International. According to the group’s website, the company exports its products to a number of countries including Australia, the United States, Malaysia, Singapore, India, Bhutan, Nepal and nations in the Middle East and Africa.