The fire is currently said to be under control but search operations are still underway. The death toll is expected to go up as the search efforts continue.
Sixteen people were rescued from the hospital.
Haydar al-Zamili, a spokesman for the local health authorities, told AFP that the “fire… ripped through the Covid isolation ward”.
He added: “The victims died of burns and the search is continuing.”
Mr al-Zamili suggested that many people could still be inside the building.
There are conflicting reports as to the cause of the fire.
One health official from Dhi Qar province said the blaze was caused by an oxygen tank explosion.
However later, officials suggested that the fire may have started due to an electric short circuit
A health worker described the difficulty of the rescue efforts.
They told Reuters: “Raging fires have trapped many patients inside the coronavirus ward and rescue teams are struggling to reach them.”
Footage uploaded to social media showed the huge fire with columns of thick smoke coming from it.
Iraq’s Prime Minister Mustafa al-Kadhimi summoned an emergency meeting with ministers and top security commanders, his office confirmed in a statement.
A Reuters reporter who was at the scene said: “Health crews carried charred bodies out of the burning hospital while many patients were coughing from the rising smoke.”
Mohamed Al-Halbousi, Iraq’s Parliament Speaker, took to Twitter to denounce the “failure” to protect Iraqis.
He wrote: “The catastrophe of Al-Hussein Hospital is clear proof of the failure to protect the lives of Iraqis, and it is time to put an end to this.”