Kallol Saha, 28, and his wife Srabani Saha, 24, were among the victims who were immediately rushed to the Chittagong Medical College and Hospital (CMCH) in unconscious state. All of them regained consciousness by 4:30pm. Of them, 13 were released from the hospital while three others will have to stay for at least another day, said Dr Purnendu Saha of CMCH yesterday evening.

Sources and relatives said after the marriage ceremony on Monday night, some members of the bridal party went to bride's house at Kattali. There they went to sleep at around 3:30am on completion of a few more rituals.

The incident of poisoning became known at around 6.00am when members of a band party, which played music during the ceremony, went into the house for tips. Despite repeated knocks on the main gate, none of the family members responded from inside, said sources.

After a few minutes, the band party members scaled the boundary wall and entered the house. They found the 16 lying unconscious in the rooms of the single-storey building. With the help of locals, they immediately took the victims to the CMCH.

The cause of the gas poisoning could not be known till filing this report at 7:00pm last night. Jharna Saha, a member of the bride's family, said that she suspects someone from outside might have sprayed poisonous gas in the rooms. Another source however said it could be an accident poisoning resulted from malfunctioning of a generator.

"The incident happened soon after the generator was switched on following a power failure," she told The Daily Star.

Police were not informed of the matter till yesterday evening.