Mauritius has raised a cyclone warning alert to maximum after Cyclone Belal brought torrential rain and flooding to the Indian Ocean island nation.

The country's meteorological service said the storm was now moving away eastwards, but warned that "other environmental risks" still existed.

At least one person has died in Mauritius, and another in neighbouring Réunion, from the storm.

It has left thousands without power, as well as heavily flooded streets.

The Mauritius Meteorological Service (MMS) said that the level 4 warning, the maximum level, was in place after the storm hit close to the country's southern coast on Tuesday morning at about 90km/h (56 mph).

It said the storm was now moving eastwards, in the direction of the Indian Ocean, at a speed of about 18km/h.

"There are no longer any risks of having cyclonic conditions over Mauritius but other environmental risks exist," it said, urging people to remain in safe places and not to go out to sea, or walk along shorelines, because of the potential for storm surges.

On Monday, Prime Minister Pravind Kumar Jugnauth confirmed one death, and criticised the MMS for its response to the storm, saying the director had submitted his resignation.

"I have to admit that the country has had a difficult time because of Cyclone Belal," he said, adding that government decisions had relied on information from the meteorological service.

"I am surprised that the arrival of the heavy rains was not anticipated by the weather services. I share the anger of many Mauritians. Those responsible will have to assume their responsibilities."

The international airport in Mauritius was closed on Monday due to the storm, although on Tuesday some flights to nearby Rodrigues appeared to be operating, with other flights cancelled. The airport urged passengers to contact their airlines for more information.

Sheets of metal clattering in the howling wind could be heard in the deserted streets of the Mauritius capital, Port Louis, on Monday, while people further south on the island were dealing with the worst of the weather.

Videos showed severe flash flooding in Port Louis, as well as cars submerged in fast-flowing flood waters.

The International Federation of Red Cross Africa said that more than 1,000 people had been evacuated, and about 8,400 people in Mauritius were without power.

Cyclone Belal has already hit nearby Réunion, leaving at least one person dead.

Despite warnings Réunion, a French overseas territory, appeared to have been spared the worst of the cyclone, as the eye of the storm passed to the north.

Jerôme Filippini, the region's prefect, said it had not had the "cataclysmic character" initially feared.