Thirty two Chinese tourists and four North Koreans have died in a major bus accident in North Korea, China's foreign ministry says.
Two Chinese nationals were also seriously injured and are in a critical condition.
A South Korean think tank, the Korea Maritime Institute, says Chinese visitors account for about 80 per cent of all foreign tourists visiting North Korea, with tourism generating about $US44 million ($A57 million) each year for the isolated country.
Chinese diplomats have rushed to the scene of Sunday's accident in North Hwanghae province, the foreign ministry said.
In a Twitter message earlier on Monday, Chinese state television's English-language channel said a tour bus had fallen off a bridge, killing more than 30 people, but later deleted the message.
State television's main Chinese-language news channel showed images of a crashed blue bus with its wheels in the air, in footage taken in pouring rain in the dark.
It showed at least one person being treated in hospital, but gave no details of casualties.
In a separate statement, China's health ministry said it was sending a team of medical experts, along with equipment and drugs, to North Korea, to help treat survivors.
The North Hwanghae province that borders South Korea is home to Kaesong, an ancient Korean capital thronged by tourists.
North Korea is a popular, if offbeat, tourist destination for Chinese, especially those from the country's northeast.
China said more than 237,000 Chinese visited in 2012, but stopped publishing the figures in 2013.
China is North Korea's most important economic and diplomatic backer, despite Beijing's anger at Pyongyang's repeated nuclear and missile tests and support for strong United Nations sanctions against North Korea.
North and South Korea are in the final stages of preparations for a summit between North Korean leader Kim Jong Un and South Korean President Moon Jae-In at the border truce village of Panmunjom on Friday.
