NASIRIYAH, Iraq - At least 36 people died in a fire in the coronavirus isolation ward at an Iraqi hospital, the second such deadly inferno in a COVID-19 unit in three months, a health official said.

The fire broke out at the Al-Hussein hospital in the southern Iraqi city of Nasiriyah late Monday and was still ongoing, according to an AFP correspondent.

Haydar al-Zamili, a spokesman for the local health authorities, told AFP that the "fire... ripped through the Covid isolation ward," and put the death toll at 36.

Five were injured, "including two in critical condition," he added.

"The victims died of burns and the search is continuing," Zamili said, noting that there were fears victims could still be trapped inside the building. The ward itself has space for 60 patients.

Iraq's interior ministry said on Facebook late Monday the fire tore through temporary structures erected next to the main building, but did not specify the cause.

The deadly blaze immediately sparked angry calls on social media demanding action and the resignation of top officials.

Sixteen people have been rescued so far, a medical source said late Monday.

Videos shared online showed thick clouds of smoke billowing from the Al Hussein hospital.

In April, a fire at a Baghdad Covid-19 hospital killed 82 and injured 110, sparked by the explosion of badly stored oxygen cylinders.

Many of the victims in the April fire were on respirators being treated for Covid-19 and were burned or suffocated in the resulting inferno that spread rapidly through the hospital, where dozens of relatives were visiting patients in the intensive care unit.

The April fire sparked widespread anger, resulting in the suspension and subsequent resignation of then health minister Hassan al-Tamimi.

Iraq -- where the oil-reliant economy is still recovering from decades of war and insurgency and many people live in poverty -- has recorded over 1.4 million Covid cases and more than 17,000 deaths.

Much of the country's health infrastructure is dilapidated and investment in public services is limited by endemic corruption.

Since the vaccine rollout began in March, Iraqi health authorities have fully inoculated only around one percent of the country's roughly 40 million people.

Vaccine scepticism and apathy are especially rife amid younger Iraqis, in a country where 60 percent of the population is aged under 25.

Earlier on Monday, a minor fire broke out at the health ministry's headquarters in Baghdad, but it was quickly contained with no fatalities recorded.