Three brothers died after inhaling toxic gas in a septic tank in Mahalchhari upazila of Khagrachhari last night.

The brothers are: Prodip Shashi Chakma, 42, Heventu Chakma, 35, and Uventu Chakma, 32, residents of Monartek village in the upazila, reports our Khagrachhari correspondent.

Uventu went to the toilet of his house around 11:25pm but suddenly his mobile phone fell into the low commode, said Semaun Kabir, officer-in-charge of Mahalchhari Police Station.

He tried to pick the mobile phone by opening the slab of the septic tank but became unconscious after inhaling the toxic gas and fell into the tank.

When the siblings came to look for their brother, Heventu and Prodip also fell into the tank after they became unconscious by the fumes.

Hearing screams of family members, locals hurried to the spot and rescued the victims. The trio was rushed to Mahalchhari Upazila Health Complex where doctors declared them dead.

Two locals -- Ripon Chakma, 22, and Bablu Chakma, 20, -- fell sick when they tried to rescue the three siblings. They are undergoing treatment at the upazila health complex.