A boat carrying at least 20 people overturned on Lake Maggiore Sunday, according to Italy's fire service, which was looking for passengers reported missing.
Nineteen people were safe after the vessel overturned off Lisanza, right at the southern end of the lake in northern Italy, Firefighter spokesman Luca Cari told AFP.
Rescue divers and a helicopter were searching for "some people reported to be missing", he said.
A firefighters' video published by the Corriere della Sera showed the helicopter flying over choppy waters, where chairs and other debris could be seen floating.
The vessel was a tourist boat which overturned in bad weather, the Corriere della Sera said.
Lake Maggiore, which lies on the south side of the Alps, is the second largest lake in Italy and a popular tourist destination.
