This image made from video shows medical staff taking an injured person inside a hospital in Hamdaniya, Nineveh province, Iraq, Wednesday, Sept. 27, 2023. AP
More than 150 people were injured by the flames, the choking smoke, or in the crush to flee the reception hall, which was reduced to charred debris and piles of twisted furniture under a partially collapsed ceiling.
"I thought there had been an explosion," said Martin Idriss, 19, who was working in the kitchen when the fire broke out Tuesday evening in the venue in the mainly Christian northern city of Qaraqosh.
"The flames were devouring the whole hall," he said.
"When I went back in, I saw the charred bodies of three children," he said, adding the venue's emergency exits had proved "inadequate" for the hundreds of guests trying to escape.
Early reports and unverified video footage online suggested flares shot up sparkling flames that ignited ceiling decorations before the fire engulfed highly flammable construction materials.
Health authorities "counted 100 dead and more than 150 injured in the fire at a marriage hall in Hamdaniyah", as the city is also known, Iraq's official INA news agency reported in what it called a "preliminary tally".
The casualty toll was confirmed to AFP by health ministry spokesman Saif al-Badr, who said most of the injured were being treated for burns, oxygen deprivation, and crush injuries.
But the director of health services in Nineveh, Mansour Marouf, on Wednesday afternoon said 94 people had died, with their bodies transported to different hospitals.
Only 30 of those had been immediately identified by their families, he told a news conference.
The Iraqi Red Crescent meanwhile reported more than 450 casualties, without providing a breakdown of deaths and injuries.
'We were suffocating'
Wedding guest Rania Waad, 17, who suffered burns to her hand, said that as the bride and groom "were slow dancing, the fireworks (flames) started to climb to the ceiling (and) the whole hall went up in flames".
"We couldn't see anything," she said, choking back sobs. "We were suffocating. We didn't know how to get out."
At the city's main hospital, an AFP photographer saw ambulances with sirens blaring and dozens of people gathering to donate blood, while bodies in black bags were being loaded onto a refrigerated truck.
On Wednesday, police and firefighters sifted through the charred remains of the reception hall where mangled metal chairs lay strewn amid the debris.
Civil defence authorities said the hall had been fitted with prefabricated panels that were "highly flammable and contravened safety standards".
The danger was compounded by the "release of toxic gases linked to the combustion of the panels", which contained plastic, they said in a statement.
"Preliminary information" suggested indoor fireworks had ignited the blaze, they said.
Nine of the venue's staff were arrested and arrest warrants were issued for its four owners, Interior Ministry spokesman General Saad Maan told AFP.
Three days of mourning
Iraqi Prime Minister Mohamed Shia al-Sudani declared three days of national mourning.
He also ordered "intensified periodic inspections" of entertainment venues nationwide to "ensure that safety measures are followed" and to "identify any non-compliant buildings".
Safety standards in Iraq's construction sector are often disregarded, and the country, whose infrastructure is in disrepair after decades of conflict, is often the scene of fatal fires and accidents.
In July 2021, a fire in a hospital Covid unit killed more than 60 people in southern Iraq.
And in April of the same year, oxygen tanks exploded and triggered a fire at a Baghdad hospital also threating Covid patients, killing more than 80 people.
Qaraqosh, like many Christian cities in the Nineveh Plains northeast of Mosul, was ransacked by jihadists of the Islamic State group after they entered the city in 2014.
The city and its churches were slowly rebuilt after the group's ouster in 2017, and Pope Francis visited it in March 2021.