Silchar, July 31 -- Four people died while cleaning an old water tank at an under-construction house in Assam's Cachar district on Friday, police said, adding that the property owner has been detained as part of the investigation.

The incident happened at an unconstructed house in the Kumarpara Joynagar area on the outskirts of Silchar town on Friday afternoon. Police said that four persons were rescued after being found unconscious inside the tank but were declared dead on arrival at Silchar Medical College and Hospital (SMCH).

"Prima facie suggests that they died of suffocation or lack of oxygen inside the tank, but we can only ascertain the cause of death once the postmortem report comes," said additional superintendent of police (cr...