A United Airlines jet was forced to make an emergency landing after plummeting mid-air following take-off. At least six people were injured after the plane jolted during the flight from Nigeria on Friday. The flight, which was heading from Lagos to Washington DC, had 245 passengers and 11 crew on board at the time.

A United Airlines flight had to make an emergency landing in Lagos, Nigeria due to a midair incident causing loss of pressure and sharp descents.

It is unclear what caused the jolt; United Airlines has said the cause was not severe turbulence, and that it is “working with aviation authorities in the US and Nigeria to understand the cause.”

A United Airlines flight experienced a mid-air crisis shortly after take-off from Nigeria, resulting in at least six injuries and an urgent return to Lagos. The Washington DC-bound Flight 613 encountered a technical problem around 90 minutes into its journey on Friday, causing a severe jolt that injured several passengers.

A United Airlines flight bound for Puerto Rico made an emergency landing at Newark Liberty International Airport on Saturday morning, according to the FAA. The flight returned to Newark around 10 a.m.

A United Airlines flight from Africa to Washington D.C. had to turn around on Thursday after a "technical issue" caused "unexpected aircraft movement," the airline said.

United Airlines said it was cooperating with U.S. and Nigerian investigators to determine what exactly happened on the flight.

A United Airlines flight from Nigeria to the US was forced to make an emergency landing in Lagos early Friday. The flight from Lagos to Washington D.C. turned back after the aircraft — a Boeing 787-8 — experienced a technical issue and "an unexpected aircraft movement,