At least 11 people were killed and 24 others rescued Sunday after the boat they were traveling in capsized off of Sri Lanka’s southwestern coast, police said.

The boat was among 19 that took part in a religious festival procession from the fishing town of Beruwala, around 60 kilometers (37 miles) south of the capital, Colombo, said police spokesman Priyantha Jayakody.

The tragedy occurred when the boats were returning from the festival.

Jayakody said in a statement that seven women and four men died. The 24 people who were rescued were being treated at a hospital.

The cause of the accident was not immediately known.

Fishing families in Beruwala travel by boat every year to the Roman Catholic church feast in the town of Kalutara.