Mauritius raised a cyclone warning alert to maximum on Tuesday and told its inhabitants to stay indoors, but said tropical storm Belal was moving away from the Indian Ocean island nation.
Gusts of winds up to around 120 kilometres an hour were pummelling the remote island, the Mauritius Meteorological Service (MMS) said in a statement.
Belal has already battered the French overseas territory of Reunion, leaving one person dead.
Cyclone Belal hit the French Indian Ocean island on Monday, moving in from the northwest packing "extreme winds", according to Meteo-France.
"The eye of the storm is passing over the Reunion Island, starting from the northern part," the meteorological service said in its latest public bulletin.
The MMS said a cyclone class warning 4, the maximum-level, was now in force on the island, a magnet for tourists attracted by its stunning white beaches and crystal-clear waters.
"The public is advised to maintain all precautions and remain indoors," the agency said.
But it said in an update at around 7am (0300 GMT) that barometric pressure was rising, "indicating that Belal has already crossed at its closest distance from Mauritius".
"However, the cyclonic winds associated with Belal are still influencing the island," the MMS added.
Severe Tropical Storm Belal is centred at about 150 kilometres south-southeast of Mauritius, and is moving eastwards at a speed of about 15 kilometres an hour, according to the MMS.