A commercial jet carrying 143 people, skidded off the run way is now "down on the river" in Jacksonville, Florida.
The city's mayor confirmed the incident.
It was a US Department of Defence plane from Guantanamo Bay that skidded off a runway into shallow water of St. John's River in Jacksonville, Florida, late Friday.
The jet travels between military bases in Cuba and Florida. There were 143 people — 136 passengers and seven crew — on board.
Jacksonville Sheriff's Office said 21 adults had been taken to local hospitals.
Spokesman for the naval air station said: "Navy security and emergency response personnel are on the scene and monitoring the situation."
It was not immediately clear what type of aircraft it was. The Department of Defence later confirmed it was a Boeing 737.
Fire and Rescue services are on the scene, working to control jet fuel escaping into the water, according to the mayor.
All passengers have been accounted for, said Jacksonville Mayor Lenny Curry. All were in good condition, none with critical injuries.
The Cuban military base's Facebook said: "All passengers have been accounted for and survived an accident tonight at NAS Jacksonville when the 'Rotator' aircraft slid off of the runway.
"Navy security and emergency response personnel responded to various passenger injuries, none of which have been reported as life-threatening.
"The thoughts and prayers of the Guantanamo Bay family go out to all those impacted by this accident."
The flight is what is called "the rotator" flight that flies out of Guantanamo on Tuesdays and Fridays.
It’s a regularly scheduled charter flight that flies from Guantanamo Bay, Cuba, to Jacksonville and then continues on to Norfolk, Virginia, said Bill Dougherty, a spokesman for Navy Region Southeast.