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

Nearly 40 people were injured when a Boeing 787-800 plane suddenly lost altitude during a United Airlines flight from Lagos, Nigeria, to Washington, D.C., early Friday, officials said.

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

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

The plane headed back to Nigeria after experiencing "unexpected movement" mid-flight on Friday, Jan. 24, according to multiple reports

A flight to Washington, D.C., returned to Nigeria after “unexpected aircraft movement” caused injuries, United Airlines said. A statement from United emailed to The Hill on Monday said that one of its flights headed for Washington,

The same United Airlines aircraft had a similar issue earlier this week, with a rapid altitude drop prompting a diversion.

Dozens of passengers sustained injuries after a Washington-bound United Airlines flight made an emergency return to Lagos for "technical" reasons.

The U.S. National Transportation Safety Board (NTSB) is investigating a United Airlines flight incident that led to passenger and crew injuries following a sudden aircraft movement. The flight, en route from Lagos to Washington D.

During a flight from Lagos to Washington, D.C., a Boeing lost 300 meters of altitude. Almost 40 people were injured in the subsequent emergency landing.

A United States flag carrier, United Airlines flight UA613, outbound from Lagos to Washington, has declared an emergency and returned to Lagos.