Iraq on Saturday buried the victims, among them many young boys, of a suicide attack that ripped through a trophy ceremony after a football tournament and killed 32 people.

The bomber, who himself looks like a teenager on a photo distributed by the Islamic State group that claimed the attack, cut through a crowd gathered after the game and blew himself up.

Babil province announced three days of mourning following the attack, that sparked condemnation from visiting UN chief Ban Ki-moon and outrage across the global footballing community.

"There are 32 dead and also 84 wounded, 12 of whom are in a critical condition," an official in Babil province health directorate told AFP.

"Seventeen of those killed are boys aged between 10 and 16," the official said.

The attack took place in the Babil province village of Al-Asriya, which lies near Iskandariyah, a town about 40 kilometres (25 miles) south of the capital.

The bomber detonated his suicide vest late afternoon on Friday as officials were handing trophies to the players after the tournament.

A video posted on social media shows one official speaking in front of a table covered with trophies and calling out the name of a player before a huge blast.

The footage cuts off with a big flash of yellow light.

- Global outrage -

"The suicide bomber cut through the crowd to approach the centre of the gathering and blew himself up as the mayor was presenting awards to the players," Ali Nashmi, an 18-year-old witness, told AFP.

The mayor, Ahmed Shaker, was among the dead, as was one of his bodyguards and at least five members of the security forces.

Pictures posted on social media of the blast site showed mangled goal posts smeared with blood.

The US State Department extended its condolences to the bereaved in a statement, as did the UN secretary general who was visiting Iraq for talks.

"I would like to take this opportunity to express my deepest condolences to the people and government of Iraq, and particularly those members of the families affected by terrorist attacks yesterday," the UN chief told reporters.

Gianni Infantino, the new head of world football's main governing body FIFA, said he was "shocked and terribly saddened".

"Around the world, football unites people. It is a very sad day, when people, going to a match together, become the victims of such violence," Infantino said in a statement.

The Asian Football Confederation also released a statement condemning the bombing.

"Football is a powerful force for good and our game has a long history of bringing people together even during conflicts around the world," it said.

"Using football and sport stadiums as a stage for these heinous acts of violence is a cowardly, completely unjust and indiscriminate act," the AFC said.

IS has been losing territory steadily in Iraq for almost a year.

In the most recent operations, Iraqi forces have been gaining ground in the western province of Anbar and have just begun their reconquest of the province of Nineveh.

Observers have warned that, as their self-proclaimed "caliphate" shrinks towards extinction, IS fighters are likely to revert to their old guerrilla tactics and ramp up suicide attacks on civilian targets.