SAN FRANCISCO?- Federal aviation officials say an Asiana Airlines flight from Seoul, South Korea, has crashed while landing at San Francisco airport. It was not immediately known whether there were any injuries.

Federal Aviation Administration spokeswoman Laura Brown says the plane was coming from South Korea and was supposed to land on runway 28 left at San Francisco International Airport. She said the sequence of events was still unclear, but it appeared the plane landed and then crashed.

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.

The airline's website says its Boeing 777 can carry between 246 to 300 passengers.

An Asiana Airlines flight from Seoul, South Korea, crashed while landing at San Francisco airport, July 6, 2013. [Photo/Xinhua]