Slippery conditions and fog are thought to have contributed to a huge highway pileup that killed 17 people in northeastern China, reports CNN.

The crash involved 56 vehicles on the Beijing-Kunming highway in China's Shanxi province around 9 a.m. Monday, according to state news agency Xinhua.

"The fog was heavy, so I drove slowly when I exit the tunnel," one driver involved in the incident told state-run CCTV. "I saw two vehicles horizontally blocking the road, so I stepped on the brake."

It had been snowing and raining before the accident, which also injured 37 people, Xinhua said.

Firefighters told CCTV that when they arrived they fought a blaze at the front of the pileup.

"While some of us manned the hoses, a chief officer led the rescue efforts of trapped personnel," firefighter Wang Ruobing said.