A twin suicide bombing has struck a village wedding north of Baghdad, killing at least 26 people and wounding dozens, a government spokesman said.

The attack, which took place late on Wednesday, began when one suicide bomber wearing an explosives-laden belt walked into the wedding party assembled in an open area in Hajaj, near the city of Tikrit, about 130 kilometres (80 miles) from Baghdad.

The bomber detonated his explosives, only to be followed by the second attacker, who blew himself up when people had gathered to help the victims of the first explosion, provincial spokesman Ali al-Hamdani said.

Twenty-six people were killed, most of them children, and up to 67 were wounded, he said.

There was no immediate claim of responsibility for the attack but suspicion is likely to fall on Islamic State, which has staged similar attacks in the past.

The wedding party was for a family that had been displaced from Iraq's western Anbar province and that is affiliated with a major anti-IS tribe there.

IS had captured Tikrit during its blitz across Iraq in the summer of 2014, when the Sunni militant group seized nearly a third of the country's territory.

Iraqi forces drove the militants from the city in April 2015, but IS has since then managed to launch deadly attacks in and around Tikrit.

IS has also used large-scale attacks in an effort to distract from its losses as Iraqi forces battle to retake all of Mosul, the country's second-largest city, from the group.

Iraqi forces in Mosul have over the past week fought their way into the heart of the western part of the city, separated by the Tigris River from the eastern sector, capturing a government complex and the city's antiquities museum where IS had destroyed priceless relics.

Mosul also fell to IS in the summer of 2014, along with Tikrit and large swathes of northern and western Iraq, but now remains the militant group's last significant urban area in the country.

AP