The Mauritius Meteorological Services said in a statement that a cyclone warning level three (out of four) was in force and advised the public to stay in a safe place, with "torrential rain conditions" expected in the coming hours.
It said the cyclone was about 170 kilometers (105 miles) west of Le Morne, which lies on the southwest of the island, and was moving east-southeast at a speed of about 12 kilometres an hour.
"On this trajectory, Belal is dangerously approaching Mauritius and it represents a threat for Mauritius," the meteorological office said.
"The radius of cyclonic winds is likely to cross the southern part of the island and Belal is expected to pass closer to the south of the island early tomorrow (Tuesday) morning."
PORT LOUIS, Mauritius - Mauritius was bracing Monday for tropical cyclone Belal that the authorities warned was "dangerously approaching" the Indian Ocean island nation after hitting the French overseas territory of Reunion.