The boat was taking 17 passengers from Ijede in the Ikorodu area of the city to Badore when it hit an object and capsized at about 10:20 AM, Ibrahim Farinloye told AFP.
"Seven people are confirmed dead. We recovered four bodies at the scene while three others died in the hospital," he said.
Boat accidents are common in Lagos as many communities and residents on islands in the city and other parts of the country travel to work, school and markets daily by boat, in some cases to avoid monster traffic jams.