San Francisco, Calif. -

A federal aviation official says an Asiana Airlines flight has crashed while landing at San Francisco airport. It was not immediately known whether there were any injuries.

FAA spokeswoman Lynn Lunsford says the Boeing 777 crashed at San Francisco Airport while landing on Saturday. 

A video clip posted to Youtube shows smoke coming from a silver-colored jet on the tarmac. Passengers could be seen jumping down the inflatable emergency slides.

Asiana Airlines is one of South Korea's two major airlines, the other being Korean Air. The airline is based in Seoul, South Korea. Its website says its Boeing 777 can carry between 246 to 300 passengers.

The airport is located about 12 miles south of downtown San Francisco.