Hanoi, Feb. 2 -- Flights in Noi Bai International Airport (NIA) in Hanoi could not take off or land, due to the unusual thick fog cloaking the capital city on February 2.

From around 2:15am to 9:00am on February 2 morning, the thick fog and low cloud cover limited visibility for pilots making it unsafe for aircraft operations. Many flights were affected, forcing the Noi Bai International Airport to activate a safety protocol .

To ensure safety, some flights had to divert their landings to other airports or postpone, flying in holding patterns to wait for better weather.

There were about 37 flights unable to land at the Noi Bai International Airport, with 12 flights diverted to nearby airports. Also, during this time frame, to ensure fl...