File photo: The flight continued to LAX without incident.

Los Angeles - An unidentified odour caused health concerns aboard a plane at Los Angeles International Airport (LAX) on Thursday.

Twenty passengers reported feeling ill, but none were hospitalised, local media reported.

The plane belonged to Spirit Airlines, an American ultra-low-cost carrier, which arrived at LAX from Atlanta around noon, LAX officials said.

According to a statement from the airline company, passengers on board reported a sweet smell in the middle part of the aircraft for a short period of time, but not anywhere else on the plane.

Flight attendants then alerted the pilots, but the smell dissipated quickly. The flight continued to LAX without incident.

LAX police said only one person who felt ill was treated. Airport authorities said all passengers then got off the plane without requesting any medical attention.