Union Urban Development Minister M. Venkaiah Naidu on Wednesday condoled the death of workers in a fire at a factory in Hyderabad that left six persons dead.

"Pained by the loss of lives in fire accident in air cooler manufacturing unit in Attapur. My condolences to the bereaved families," Naidu tweeted.

At least six workers were killed in the fire that broke out in an air cooler manufacturing unit in Hyderabad on Wednesday morning. 

The cause of the fire is suspected to be a short-circuit. The owner had locked the factory from outside, making it difficult for the workers to escape, the official said.

Police have arrested factory owner Pramod Kumar.