Smog causes low visibility in the city of Dalian, Northeast China's Liaoning province, Nov 23, 2013. [Photo/Asianewsphoto]

SHENYANG - Heavy smog has led to closed highways in northeast China on Saturday and Sunday, according to local authorities.

Three highways in Liaoning province were completely closed due to low visibility, said the provincial transportation department on Sunday. Sections of other highways in the province were also closed.

Visibility was less than 50 meters in some smog-affected areas in Liaoning over the past two days.

Railways and airports in Liaoning were not affected, but the smoggy weather forced the Harbin Taiping International Airport in Heilongjiang province to cancel all 209 inbound and outbound flights on Saturday, in addition to the closure of major highways.

Snowstorms are forecast to sweep northeast China starting Sunday night, which is expected to end the smoggy conditions.