Visibility was so poor that 11 flights were diverted from Noi Bai to other airports for landing on the morning of December 7, an airport official said.

The national flag carrier Vietnam Airlines had to divert three flights, while low-cost carrier Vietjet Air switched two flights to land at Cat Bi Airport in Haiphong City. Meanwhile, some flights operated by foreign airlines had to change their landing destinations to airports in Danang and Hong Kong.

Many other flights departing Hanoi this morning had to be delayed until after 8 am due to the bad weather.

According to Noi Bai Airport, this dense fog rarely appears at this time of the year. It usually occurs in March. Thanks to its renovated lighting system, the number of flights affected by the bad weather has been reduced this year.