A tropical cyclone is bearing down on Mauritius bringing 75mph winds forcing authorities to close its port and airport.

Thousands of islanders have scrambled to shelters as authorities declared a class III alert for the category three storm which is due to "pass very close to" the Indian Ocean nation tomorrow morning.

In a statement, the island's meteorological service: "On this trajectory, tropical Cyclone Berguitta is dangerously approaching Mauritius and represents a direct threat to the island."

Winds of up to 75mph could come tonight as the storm approaches, the service said earlier.

The category three storm is passing close to the island (
Image:
@rahul_latchman /Twitter)
Damage has already been caused on the island because of powerful winds (
Image:
@rahul_latchman /Twitter)

Authorities closed the island's airport from 7am today (3am GMT) until further notice.

While Port Louis Harbour, the main port, was also shut.

It is the country's principal gateway and handles about 99 percent of external trade, including key imports for the country's population of 1.3 million such as food and oil.

Etienne Sinatambou, the Minister for Environment and also head of the National Crisis Committee, told a news conference Wednesday afternoon about 2,000 people had been received in 43 storm shelters around the island.

Thousands of people have fled to shelters (
Image:
@rahul_latchman /Twitter)

An association of vegetable farmers told local media their fields had been flooded and that the prices of fresh produce would likely jump in coming days.

Images posted on various social networks platforms showed several roads in the coastal regions of the island flooded.

About 300 households were without electricity, according to the Central Electricity Board (CEB).

An aerial image of the cyclone heading towards Mauritius (
Image:
Nasa)

Many residents fear Berguitta will cause extensive damage when it makes landfall, and the island of Reunion was also on alert as the cyclone approached.

Soobiraj Sok Appadu, ex-director of the meteorological service, told a radio station he estimated the cyclone might shave between 1 to 2 percentage points from the country's GDP.

In February 1994, Cyclone Hollanda killed two people, destroyed 450 homes and caused $135 million in damage when it hit Mauritius.