NEWARK, NEW JERSEY (AP) - Maintenance crews on Thursday (Jan 16) were inspecting a United Airlines jetliner that returned to New Jersey's Newark Liberty International Airport after it experienced engine trouble and flames were seen near a wing.

Flight 1871 was headed to Los Angeles with 168 passengers and six crew members on Wednesday night when the problem occurred, airline spokesman Charles Hobart said.

It was not clear what went wrong, but it was "an unsettling experience for some of our customers", Mr Hobart said.

Video showed flames soon after the Boeing 757 had taken off.

A passenger told WABC-TV that it appeared fire was coming from an engine.

"I didn't know what was happening," passenger Gabrielle Guzy said.

"My sister said she thought it was lights, but I knew it was fire from the engine. I kept reassuring myself we'd be OK because we had only been in the air for a minute."

The flight landed safely and passengers deplaned normally.

No one was injured.

The airline arranged for a different aircraft, and the passengers resumed their trip to Los Angeles early on Thursday.