Twenty-one flights were cancelled by Dubai Airports last night (December 31) due to thick fog in the emirate, a report said.

The emirate's airport operator stressed that it is working with its strategic partners and carriers to restore flight schedules, reported Wam, the Emirates official news agency.

"Severe fog in Dubai last night has caused numerous delays to Emirates flights arriving and departing at Dubai International Airport," a spokesperson for Emirates Airline said.

The carrier apologised for the inconvenience caused, and said that the safety of its passengers and crew is of utmost importance and will not be compromised.

Emirates urged customers to check their flight status for the latest information regarding their flights.

Dubai's budget carrier flydubai said since last Wednesday, thick fog has reduced visibility to less than 100 metres, sometimes, affecting its flights and operations at Dubai International Airport and Al Maktoum International Airport.

Tens of flights were cancelled, delayed or diverted to other airports, disrupting passengers' schedules, a spokesperson for flydubai noted.

The carrier spared no effort to minimise the effect of this "exceptional situation" on passengers and restore schedules to normal as soon as possible, the spokesperson said, and stressed that the safety of passengers and crew is a top priority.