"The closures were caused by the loss of power to a critical runway backup system required during foggy conditions," a Dubai Airports statement said.
Airport authorities confirmed that 50 flights were diverted to other airports in the region including Dammam, Muscat and Bahrain, Dubai World Central, Al Ain, Doha and Abu Dhabi.
"As further flight delays are anticipated as a result of the disruption, passengers are advised to check with their airline or airline websites for further information on flight arrival and departure times,'" it said.
Airport authorities said they were working with airlines, air traffic and ground services staff to restore operations, clear the backlog and limit customer inconvenience.
The thick fog also caused havoc on the roads with four accidents reported on the Dubai-Abu Dhabi motorway early today as cars collided in reduced visibility, Khaleej Times reported.
"I saw four accidents with two pile-ups of about 3-4 cars each before entering Abu Dhabi This was all before Shahama and in two cases the cars were badly damaged," said Fares Sumairi, a motorist said.
Dubai Airport, which is spread over an area of 8,640 acres of land, is the 13th busiest airport in the world by passenger traffic and the 4th busiest airport in the world by international passenger traffic. The airport is an important passenger traffic hub in the region.
