Seven persons have succumbed to the burn injuries after leakage of gas from an LPG cylinder triggered fire and explosion inside a room on the outskirts of Gujarat's Ahmedabad city, police have said.

The incident took place on Tuesday night (July 20), but the victims - labourers and their family members - died over the last couple of days during treatment, said S S Gameti, sub-inspector of Aslali police station in Ahmedabad rural on Friday.

Besides men, the deceased included children and women, he added.

"Some labourers working in a factory and their family members were sleeping in a small room when gas from their LPG cylinder started leaking on the night of July 20. When their neighbour knocked on their door to alert them, a labourer got up and switched on the light, which caused an explosion due to concentration of gas," Gameti said.

"Ten persons were sleeping there at that time and all of them received severe burn injuries as fire engulfed the room. While three persons died during their treatment on Thursday, four others succumbed to the injuries at a hospital on Friday, he said.

Three persons are undergoing treatment, the official added.