At least eight people were killed, and 24 others critically injured after a devastating fire swept through an illegal plastics factory outside the Bangladeshi capital Dhaka, according to local police on Thursday.

"One person burnt to death on the spot and 33 workers were critically burnt. Seven of them later died in Dhaka Medical College Hospital," said the police chief Shah Zaman.

Zaman said the factory was operating illegally, adding scores of firefighters battled for three hours to bring the fire under control.