(CNN) -- Eleven children from the same extended family died over the weekend in a lake in Brazil after the boat they were in overturned, police said.
The accident Sunday took the lives of one 16-year-old, and 10 children ages 1 to 11, Ailton Martins Campos of the military police told CNN.
The incident happened at a Sobradinho Lake in Bahia state, in eastern Brazil.
Sixteen members of the same extended family plus two guides boarded a motorboat for a trip on the lake, Martins Campos said. The boat overturned about a half-mile (1 km) from shore, near the town of Pilao Arcado, he said.
The military police would not comment on the cause of the accident, but local media reported that the area is known for strong winds. Other media outlets reported that the boat was designed to only hold three to six people, not the 18 that were aboard that day.
Only the adults on the boat, who were able to swim to shore, survived, Martins Campos said.
According to local reports, more than 20 police, soldiers and civilians worked in the water Sunday night to try to recover the bodies. The last of the bodies was found Tuesday.
Funeral services for nine of the victims will be Wednesday in Pilao Arcado.