A Delta Airlines plane dumped jet fuel on a primary school playground as it prepared to land at Los Angeles International Airport.
56 children and adults were treated for skin or lung irritation following the fuel dump by the aircraft just before midday (8pm, UK time) on Tuesday.
Los Angeles County Fire Department confirmed the substance was jet fuel and that several patients suffered minor injuries.
Delta said in statement that one of its planes was forced to turn back to the airport shortly after take off due to "an engine issue" and carried out an "emergency fuel release".
It said: "Shortly after takeoff, Flight 89 from LAX to Shanghai experienced an engine issue requiring the aircraft to return quickly to LAX.
"The aircraft landed safely after a release of fuel, which was required as part of normal procedure to reach a safe landing weight."
"We are in touch with Los Angeles World Airports and the L.A. County Fire Department and share concerns regarding reported minor injuries to adults and children at a school in the area."
None of those treated needed to be taken to a hospital, it said.
“70 firefighters and paramedics on-scene and committed to providing care for those injured. FFs working to confirm substance dropped by aircraft, although initial reports stated smell of jet fuel in area,” the LA fire department wrote on Twitter.
In its latest update, the service wrote: “Patient count updated to 17 children, nine adults. All minor injuries with no transports to local hospital from school. There are no evacuation orders for the immediate area. Substance was confirmed JET FUEL.”
The fire department did not immediately identify the school but the Los Angeles Times reported that it was Park Avenue Elementary School in the Los Angeles suburb of Cudahy, on the flight path to LAX.
There were no evacuation orders for the immediate area.
