NEW DELHI -- A fire broke out in the intensive care unit of a hospital in western India early Friday, killing 13 COVID-19 patients, a hospital official said.

The fire on the second floor of the hospital has been extinguished and some patients requiring oxygen have been moved to nearby hospitals, said Dilip Shah, CEO of Vijay Vallabh hospital in the Virar area on the outskirts of Mumbai.

Shah said there are 90 patients in the hospital, about 70 kilometres north of Mumbai, India's financial capital.

The cause of the fire is being investigated, he said.

The fire comes amid a massive upsurge in coronavirus cases in Maharashtra state, the worst hit in the country.

On Wednesday, 24 COVID-19 patients on ventilators died in a hospital in Nashik, another city in Maharashtra state, when their oxygen supply was interrupted by a leak in a supply line.