Scores of people are feared dead as a ferry capsized in Lake Victoria on Thursday afternoon.
The ferry known as MV Nyerere operated between Bugolora and Ukala islands in Mwanza, Tanzania.
In a statement confirming the incident, the Tanzanian Ministry of Construction, Transport and Communication said a rescue mission was on.
"The Tanzanian Electrical and Mechanical Services Agency (Temesa) would like to inform the public that the ferry connecting Bugolora islands in Ukerewe district, Mwanza province, capsized in the afternoon," read the statement.
"Temesa urges members of the public to be patient as more details about the unfortunate incident continue to be released."
Temesa Spokesperson Ms Theresia Mwami said the exact number of casualties had not yet been established.
"The casualties are not known. Rescue efforts are on ... we shall soon establish that," said Ms Mwami.
However, reports from a local FM station in Mwanza indicated that the ferry had more than 400 people on board at the time of the incident and that majority may have drowned.