YINCHUAN, Dec.1 (Xinhua) -- Heavy fog continued to shroud northwest and northeast parts of China Tuesday, causing fatal road accidents, closure of highways and delay of flights, local authorities said.

    The affected areas include the northeastern provinces of Heilongjiang, Jilin and Liaoning, Shaanxi Province and Ningxia Hui Autonomous Region in the northwest and Tianjin, a port city neighboring Beijing.

Photo taken on Dec. 1 shows traffic jam on a highway in northest China Tuesday. Heavy fog continued to shroud northwest and northeast parts of China Tuesday, causing fatal road accidents, closure of highways and delay of flights.  (Xinhua Photo) Photo Gallery>>>

     Two people died after a bus and a truck collided Tuesday on an expressway in Yongning County of Ningxia Hui Autonomous Region. Initial investigation showed that the accident was caused by the fog, said county traffic police.

    Fog has caused a total of 83 road accidents in Yinchuan City, capital of Ningxia.

    The meteorological station of Ningxia said the visibility in Yinchuan was less than 50 meters and that on some parts of the expressway linking Ningxia and northwestern Qinghai Province the visibility dropped to less than 5 meters.

    The meteorological station of northeast China's Liaoning Province issued Tuesday the 20th fog alert since Nov. 3, saying fog is shrouding most parts of central Liaoning and the visibility of the province's Shenyang and Dalian cities was less than 200 meters.

    All of the fifteen expressways leading into Liaoning are closed. More than 100 flights to and from a Shenyang airport were delayed and so were most of the flights at Dalian airport, said the provincial traffic authorities.

The picture taken on Dec. 1, 2009 shows a damaged van at the traffic accident site in Mulan County, northeast China's Heilongjiang Province. At least six people have been confirmed dead after a mini-bus collided with the van in the province, local officials said Tuesday. The accident happened on Hazhao Road in Liuhe Township, Mulan County, at about 7:40 a.m. (Xinhua/Wang Jianwei) Photo Gallery>>>

    Four expressways in northwestern Shaanxi Province were partially closed due to the fog that had reduced visibility to less than 200 meters, the provincial traffic police said.

    Three expressways with visibility of less than 20 meters in northeastern Jilin Province were closed, said the provincial traffic police.

    The visibility in most part of Tianjin Municipality was less than 50 meters, according to the meteorological station.

    All the expressways in Tianjin were closed and all the flights from a local airport were delayed, said municipal traffic police.

    In Harbin City, capital of northeastern Heilongjiang Province, four expressways were partially closed and 20 flights were delayed as fog reduced visibility to less than 50 meters, municipal traffic police said.