The blast targeted a game taking place in the town of Tal Afar, around 60km west of the city of Mosul.
A local police official said a car bomb exploded at about 6pm local time (1500GMT) near a crowd of spectators.
As people fled the scene of the first blast, two more bombers activated explosive belts in the crowd, other sources said.
Local hospital officials put the number of injured at 125.
Many of the wounded were taken by ambulance to Dahuk, 95km away, because local hospitals were unable to cope with the influx of wounded spectators.
Tal Afar is a predominantly Shia Turkomen town.
Friday's attacks follow blasts in the city last October and July that left dozens of people dead. In March 2007, 152 people were killed when truck bombs targeted markets in the town.
The bombing comes as Iraq reels from a series of coordinated attacks carried out in 10 cities on Monday which left 119 people dead.
There are fears that the political deadlock following Iraq's inconclusive election two months ago is fuelling a new wave of sectarian violence.
PHOTO CAPTION
Map of Iraq locating the town of Tal Afar, around 60km west of the city of Mosul.
Agencies