A Boeing 777 jet has crashed while attempting to land at San Francisco airport, US aviation authorities confirmed on Saturday.

The Federal Aviation Administration (FAA) confirmed that a plane, thought to be operated by Asiana Airlines and reported as Asiana 214, came down at the international airport. A Boeing 777 can carry up to 300 passengers. There was no immediate word on any casualties.

Footage from the scene of the accident showed billowing smoke coming from the plane, which reportedly encountered problems as it prepared to touch down.

Fire fighters are on the scene. It was reported that the plane was an inbound flight from Seoul, South Korea.

A plane-spotter, Anthony Castorani, told CNN he heard a "pop" as the plane landed, followed by a brief fireball at which point the jet began to cartwheel. Castorani, who was watching aircraft land from a nearby hotel room, said there was no indication that the airport was prepared for an emergency landing.

"It was coming in very nicely," he told CNN. But as it landed he witnessed a larger plume of smoke from the landing gear than is usually seen. After a "pop" he saw a brief fire take hold at which point the plane's tail became detached.

"[The plane] lifted and began to cartwheel," Castorani added.

Footage of the wreckage confirmed that the tail had come off. The main body of the plane showed extensive fire damage.

A man who claims to have been on board the flight posted a picture of passengers leaving the plane via Twitter.

In follow up tweets, David Eun said that the majority of passengers seemed OK and that the injured were evacuated from the stricken plane.

The National Transportation Safety Board said it was sending a team of investigators to San Francisco. An NTSB spokeswoman, Kelly Nantel, said the NTSB chairman, Deborah Hersman, would head the team.

Asiana is a South Korean airline, second in size to national carrier Korean Air. It has recently tried to expand its presence in the United States; it has also joined the Star Alliance network.

The 777-200 is a long-range plane from Boeing. The twin-engine aircraft is one of the world's most popular long-distance planes and is often used for intercontinental flights of 12 hours or more. The airline's website says its 777s can carry between 246 to 300 passengers.