An explosion from a plastic bottle containing dry ice at a Los Angeles International Airport terminal caused up to four flights to be delayed, authorities said.
FBI spokeswoman Laura Eimiller said a chemical reaction caused the explosion on Sunday evening in an employee bathroom in Terminal 2.
No injuries were reported, but as a precaution authorities closed the terminal and examined the area for evidence.
Ms Eimiller said the bathroom was in a restricted area of the terminal that was not accessible to the public.
Airport police sergeant Karla Ortiz said officials temporarily halted security screening, which led to the delay of up to four departing flights.
Investigators were trying to determine how the bottle ended up in the bathroom.