Los Angeles: A sea of flame retardant foam has flooded the streets around an airport hangar in the US state of California.

The fire retardant foam, technically an ‘aqueous film-forming foam,’ began to fill a street in Santa Clara next to Mineta San Jose International Airport just on Friday, according to San Jose Police.

Cleanup of the foam began by mid-afternoon but Santa Clara police said the ‘massive operation’ would likely take several hours, USA Today reported.

Police set up a roadblock to keep people from driving or walking through the fire retardant foam.

Emergency personnel on the scene told the San Francisco Chronicle and assembled onlookers that the foam was not dangerous, but only a mild skin irritant.