A fire that raced through a hall hosting a Christian wedding in northern Iraq killed at least 100 people and injured 150 others, authorities said Wednesday, warning the death toll could rise higher.

The fire happened in Iraq’s Nineveh province in its Hamdaniya area, authorities said. That’s a predominantly Christian area just outside of the city of Mosul, some 335 kilometers (205 miles) northwest of the capital, Baghdad.

Television footage showed flames rushing over the wedding hall as the fire took hold. In the blaze’s aftermath, only charred metal and debris could be seen as people walked through the scene of the fire, the only light coming from television cameras and the lights of onlookers’ mobile phones.

Survivors arrived at local hospitals, receiving oxygen and bandaged, as their families milled through hallways and outside as workers organized more oxygen cylinders.

The health department in Nineveh province raised the death toll to 114. Health Ministry spokesman Saif al-Badr earlier put the number of injured at 150 via the state-run Iraqi News Agency.

“All efforts are being made to provide relief to those affected by the unfortunate accident,” al-Badr said.

Prime Minister Mohammed Shia al-Sudani ordered an investigation into the fire and asked the country’s Interior and Health officials to provide relief, his office said in a statement online.

Najim al-Jubouri, the provincial governor of Nineveh, said some of the injured had been transferred to regional hospitals. He cautioned there were no final casualty figures yet from the blaze, which suggests the death toll still may rise.

There was no immediate official word on the cause of the blaze but initial reports by the Kurdish television news channel Rudaw suggested fireworks at the venue may have sparked the fire.

Civil defense officials quoted by the Iraqi News Agency described the wedding hall’s exterior as being decorated with highly flammable cladding that were illegal in the country.

“The fire led to the collapse of parts of the hall as a result of the use of highly flammable, low-cost building materials that collapse within minutes when the fire breaks out,” civil defense said.

It wasn’t immediately clear why authorities in Iraq allowed the cladding to be used on the hall, though corruption and mismanagement remains endemic two decades after the U.S.-led invasion that toppled Saddam Hussein.

While some types of cladding can be made with fire-resistant material, experts say those that have caught fire at the wedding hall and elsewhere weren’t designed to meet stricter safety standards and often were put onto buildings without any breaks to slow or halt a possible blaze. That includes the 2017 Grenfell Fire in London that killed 72 people in the greatest loss of life in a fire on British soil since World War II, as well as multiple high-rise fires in the United Arab Emirates.

The fire was the latest disaster to strike Iraq’s shrinking Christian minority, which over the past two decades has been violently targeted by extremists first from al-Qaida and then the Islamic State militant group. Although the Nineveh plains, the historic homeland, was wrested back from the Islamic State group six years ago, some towns are still mostly rubble and lack basic services. Many Christians have left for Europe, Australia or the United States.

The number of Christians in Iraq today is estimated at 150,000, compared to 1.5 million in 2003. Iraq’s total population is more than 40 million.