A passenger plane with 43 people on board crashed into Tanzania's Lake Victoria on Sunday as it approached the northwestern town of Bukoba.
The accident is being blamed on bad weather.
43 people, including 39 passengers, the two pilots and two crew members, were on the flight from the economic capital Dar es Salaam to Bukoba, a town on the shores of the lake, Africa's largest and the source of the Nile.
Rescuers on Sunday afternoon worked to recover survivors and lift the plane out of the water using cables and cranes.
Commander of Police, Kagera province, said: "It is true that there has been an accident in Kagera province and everything is under control as all rescues and safety equipment have been deployed to help out.
"We have managed to save quite a number of people and we will give a brief statement after we finish with our rescue efforts."
The French-Italian-built ATR 42 plane was operated by Precision Air, which is Tanzania's largest private airline and is partly owned by Kenya Airways and operates flights to popular tourist destinations such as the Serengeti National Park and the Zanzibar archipelago.
William Mwampaghale explained: "When the aircraft was about 100 metres midair, it encountered problems and bad weather.
"It was raining and the plane plunged into the water. Everything is under control. The army's head of rescue missions and firefighters from the province of Kagera are on the scene.
"They are fully equipped to deal with rescues and safety. Rescue efforts are currently underway in order to retrieve the aircraft."
At least 26 people have been rescued and evacuated to a hospital.
Tanzanian President Samia Suluhu Hassan has expressed her condolences to those affected by the crash and asked people to remain calm while the rescue operation continues.
Sunday's accident comes five years after 11 people were killed when a plane belonging to a safari company crashed in northern Tanzania.