Video footage showed patients jumping out of windows on Friday from the hospital's lower levels and firefighters carrying people out.

The country's emergency response unit had initially said nine people had died, but Transport Minister Lucian Bode later said there had been a miscommunication between firefighters and hospital staff.

Firefighters extinguished the fire at the hospital in the eastern city of Constanta, having brought in additional teams from nearby counties.

Enraged relatives of the patients gathered outside the hospital in protest and prosecutors have opened an investigation into the causes of the fire.

This is Romania's third deadly hospital fire in less than a year.

In February, a fire killed four patients at a COVID-19 hospital in the capital Bucharest. Ten people died in November in an intensive care unit at the Piatra Neamt county hospital.

"I am appalled at the tragedy," President Klaus Iohannis said in a statement.

"It is a new terrible drama which confirms the lacking infrastructure of Romania's healthcare system, placed under unimaginable pressure by the fourth wave of the pandemic."

Even before the pandemic, Romania's health care system had been under pressure, dogged by corruption, inefficiencies and politicised management. The country has one of the European Union's least developed healthcare infrastructures.

The state has built one hospital in the last three decades, spends the least on healthcare in the EU and tens of thousands of doctors and nurses have emigrated.

Australian Associated Press