The death toll from a boat accident in eastern India rose to 26 on Sunday, a senior official said, warning of more casualties with rescue workers still scouring the waters.

The non-motorised wooden boat, packed beyond capacity with revellers returning from a kite festival, capsized Saturday in the Ganges river near Patna, the capital of Bihar state.

The exact number of missing could not be ascertained due to the absence of a passenger list but police said the boat was carrying at least 40 people.

Rescue workers were working round the clock looking for survivors, Anirudh Kumar, joint secretary of the state disaster management authority said.

“Workers pulled out 22 bodies in the night and this (Sunday) morning four more bodies were recovered,” he told AFP by phone.

“The boat capsized not very far from the shore. Some people managed to swim to safety. But we are fearing the number of dead could go up further.”

Among those to survive the tragedy was an 18-month toddler, now recovering in a city hospital, Kumar said.

The revellers were on their way back from the annual Hindu harvest festival of Makar Sakranti, marked by kite-flying and other festivities.

State Chief Minister Nitish Kumar has ordered an inquiry into the accident and announced compensation of 400,000 rupees ($5,900) for the families of the victims.

Indian Prime Minister Narendra Modi also condoled the deaths while cancelling an event he was scheduled to attend in Patna on Sunday.

Boat accidents are common in the country, mainly because of overcrowding, poor maintenance, lax regulations and a lack of life jackets and other safety equipment.

Some 20 people died after a ferry capsized in a rain-swollen river in India's northeastern state of Assam in September 2015.

More than 100 people lost their lives in 2012 in Assam when a boat sank in the Brahmaputra river during a storm. -AFP