A fire that swept through a crowded wedding hall in a northern Iraqi town killing more than 100 people was blamed on "gross negligence" and lack of safety measures, the results of a government investigation into the disaster said.

The investigation results, announced at a news conference on Sunday by interior minister Abdul Amir al-Shammari, said the owner of the hall and three other staff members had allowed 900 people into the venue when it was designed for a maximum of 400.

“The fire was accidental and unintentional and occurred due to gross negligence,” the investigation findings said.

“Using flammable decoration helped the fire to spread quickly and transformed the hall to a fireball,” Shammari said.

The blaze trapped people inside the wedding hall and rescue teams struggled to reach them because exit doors were few and small, Shammari said.

At least 150 people were injured in the fire, which was in the Christian town of Hamdaniya - also known as Qaraqosh.

The interior minister put the death toll at 107 and said the investigation panel had proposed that the government should provide financial support to families of the dead and injured.

The investigation also made recommendations that legal action should be taken against local officials.

Prime Minister Mohammed Shia Al-Sudani visited victims of the blaze at two local hospitals on Thursday and pledged to hold those responsible to account.