"They were just handing the trophy to the winners, the suicide attacker blew himself up in the crowd," a police captain from the village, Al-Asriya, told AFP.
The village is near Iskandariyah, a town about 40 kilometres south of the capital.
The police captain said more than 50 people were also wounded in the blast.
A source at Iskandariyah hospital confirmed the toll, warning that the casualties figure were preliminary and could rise.