Three people were charred to death after a fire caused by a generator explosion trapped the victims inside a photocopy shop in a West Bengal town near Kolkata Friday.

Officials said the fire first broke out on the ground floor of a Life Insurance Corp of India (LICI) building at Barasat in Kolkata's adjacent North 24-Parganas district and soon engulfed all the three floors and a photocopy shop near it, causing the deaths.

Three employees of the shop were charred to death in the blaze as they failed to come out.

'After primary investigation, we think the fire broke out due to a electrical short circuit. There were also some barrels containing diesel at the generator room, which reinforced the blaze,' West Bengal Fire Services Director Gopal Bhattacharya told IANS.

He said five fire engines brought the blaze under control within an hour.

'The leaping flames also caught some vehicles parked outside of the building,' he said.

'It was an accident. We don't suspect any foul play,' he said.

'The fire was probably caused by the use of poor quality of wires in the generator room of the building,' Bhattacharya said.