The village of Al-Asriya, south of Baghdad, prepared Saturday to bury its sons, killed when a suicide bomber blew himself up after a football tournament.

The attacker, who himself looks like a teenager on a photo distributed by the Islamic State group that claimed the attack, cut through the crowd when trophies were being presented.

"There are 32 dead and also 84 wounded, 12 of whom are in 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 village of Al-Asriya 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 local officials were handing trophies to the players after a local tournament.

A video posted on social media shows a local 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.

"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 eyewitness, 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 United States state department extended its condolences to the bereaved in a statement, as did the United Nations special envoy to Iraq.

"Pictures posted on social media of the blast site showed mangled goal posts smeared with blood," Jan Kubis said in a statement.

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.