A blaze tore through Dubai's Torch Tower for the second time in two years as firefighters frantically worked to save the 84-story building.
The Dubai Civil Defense said the fire burned for at least two hours early Friday before firefighters started cooling the building.
There were no immediate reports of injuries, the Dubai Media Office tweeted.
Video posted to social media showed a line of fire up one side of the building and falling, flaming debris.
Witness Samer Fathallah told CNN he thought the fire had engulfed 30 to 40 residences. Two cars in the parking deck were set on fire by falling debris, he said.
Firefighters fought the fire from inside the building, and the crowd gathered 500 meters away could see water shooting out of the affected units.
The Torch was the site of a massive fire in February 2015.
There were no deaths or injuries, and that fire was out three hours after it began, the Civil Defense Office said.
The Torch was the world's tallest residential tower when it was completed in 2011, according to the building's developer, Select Group. It contains 682 residential units with 24-hour security and concierge, and six retail spaces. It has 84 floors, the developer's website says.