At least 22 people, many of them children, were killed after a double-decker tourist boat capsized in the southern Indian state of Kerala on Sunday evening. Rescuers had found eight people with injuries by the next morning, with four of them in critical condition.

Some passengers were trapped under the vessel, which was concluding a five-mile voyage in the estuary of the Purapuzha River near the town of Tanur on India’s southwestern coast. The boat was carrying more than 40 sightseers, according to survivors, when it capsized at around 7 p.m.

“The boat was overcrowded,” said Abdul Nazar, a local police officer. It did not have enough life jackets, other officials as well as survivors said. Local media reported that the vessel also lacked a required safety certificate, and was not permitted to operate that late in the day.

Among the victims were seven children, the youngest 10 months old, and 11 victims were from one family, according to the authorities, who haven’t been able to verify how many people were aboard the boat at the time of the accident. Five passengers swam ashore and were being treated at a nearby hospital, according to V. Abdurahiman, a local legislator, who is overseeing the rescue operation.