The authorities in Nigeria said that the United Airlines plane had to return to Lagos, Nigeria, after the episode. Six people were treated at a hospital, officials said.

In an update, Nigerian officials said an additional 27 passengers and 5 crew members suffered minor injuries in the incident. In all, 38 were hurt.

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

Six were injured on a United Airlines flight from Lagos to Washington after the plane had a technical issue that caused an "unexpected movement."

Six people were seriously injured when a United Airlines flight experienced sharp drops in speed during its journey to Washington Dulles International Airport.

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.”