The United Airlines Boeing plane that turned around midflight after departing Sydney, Australia earlier this week suffered a hydraulic leak, the airline says.

United Airlines Flight 830, which was bound for San Francisco on Monday, returned to Sydney Kingsford Smith Airport "due to a maintenance issue," the airline told FOX Business in a statement, adding Thursday that the issue was a hydraulic fluid leak.

A video captured by an aviation enthusiast appeared to show fluid leaking from the wheel area of the Boeing 777-300 aircraft.

The plane was then greeted on the tarmac by fire crews when it came back to Sydney.  

"The plane landed safely and passengers deplaned normally at the gate," United Airlines said. "We provided accommodation overnight for passengers and rebooked them to San Francisco the next day." 

The airline added that the plane was carrying 167 passengers and 16 crew. 

Data from FlightAware indicates the plane was traveling over the Pacific Ocean before turning around and arriving back in Sydney about two hours later.  

The incident happened the same day that at least 50 people were injured when a LATAM Airlines Boeing 787-9 Dreamliner experienced a "strong movement" on a flight to New Zealand. 

"The plane dipped so dramatically into a nose dive for a couple of seconds and around 30 people hit the ceiling hard," said Daniel, one passenger on board that aircraft, according to the New Zealand Herald.    

Last Thursday, a United Airlines Boeing 777-200 lost a wheel while taking off from San Francisco on a flight to Japan and had to land in Los Angeles.  

The tire that fell off damaged several parked cars at San Francisco International Airport.