BEIJING (AFP) - Friends and relatives of Chinese passengers onboard the South Korean-owned passenger jet that crashed at San Francisco airport killing two and injuring 182 were anxiously waiting on Sunday for news of their loved ones.

Chinese nationals made up 140 of the 290 people aboard the Asiana Airlines Boeing 777 which burst into flames after it landed short of the runway.

Among them were around 60 students and several teachers, with only one slightly injured and two unaccounted for, the Xinhua state news agency said.

The friend of one student told AFP she was waiting at San Francisco airport, frantically phoning people in China to find out details.

"My best friend is on the plane. I've been at the airport all day, trying to contact my friends in China to get updates on the accident," she told AFP over Sina Weibo, China's version of Twitter.

"I was really scared and am still trying to recover," she said.

"You just never know when planes will have a problem."

Xu Da, a Chinese passenger on board, described the dramatic incident on CCTV.

"I noticed the plane was flying quite low when landing, and as it was just about to land the plane suddenly accelerated and the nose started to rise," he said. "But at the time the plane was flying extremely low already."

He added: "I felt a shock. The oxygen masks fell down and a bad smell began to spread throughout the plane. I could also see sparks in the front part of the plane."

Once the plane landed the cabin was a "mess", the back of the plane had a large hole and the kitchen there had disappeared, he described on Sina Weibo.

Mr Xu and his wife collected their luggage and rushed out the makeshift exit at the back.

He posted photos showing people waiting outside while thick black smoke billowed from the plane, and then later from inside the airport, though the images could not be verified.

"I feel very fortunate," he wrote a little later, before posting another photo from a car leaving the scene.

Other travellers were left waiting for their flights as the airport shut down immediately after the incident before reopening a few runways.

A Chinese pilot surnamed Wang who was waiting to fly to Hong Kong told the official China News Service he was still trying to reach his friend on board.

"I haven't got in touch with him yet," he was quoted as saying.

When the plane crash-landed, he said, "the slide was released very quickly and the plane caught fire. The fire got bigger and bigger. First there was white smoke, then black smoke."

CCTV urged survivors and their loved ones to post information on the online messaging system WeChat so they could find one another.