A teacher also suffered severe injuries.
Grainy footage from the accident site that was posted Chinese social media showed flames leaping from the sides of a tall vehicle, while local media published photographs of black smoke billowing out of the tunnel's entrance.
Reuters could not independently verify the accuracy of the images or videos.
The South Korean Consulate in the Shandong provincial capital of Qinghao had earlier said that ten South Korean died in the accident. Consular officers had been sent to the site, it said.
China's state news agency, Xinhua, reported that one of the Chinese victims had a South Korean identity card.
Beijing does not release statistics on the total number of accidents each year, but the World Health Organization estimated in 2013 that around 250,000 people were killed on China's roads that year.
Beijing has vowed to clamp down on dangerous driving, but the rapid growth in car ownership and relatively lax checks on driving ability have made difficult to curb the number of accidents, especially on rural roads.
