Tropical cyclone Enawo struck Madagascar on Tuesday, buffeting the island with powerful winds, heavy rain and high seas and threatening to cause chaos in the capital, the country's weather agency said.
"Enawo made landfall and struck... with terrible winds of 210 km/h (130 mph) with some gales of 290 km/h" from around midday (0900 GMT) Tuesday, according to the head of the Madagascar's Weather Service, Samueline Rahariveloarimiza.
She warned that the capital Antananarivo was in "imminent danger" with the cyclone expected to reach the city of 1.4 million people on Wednesday.
The entire north of the island nation, which lies 400 kilometres (250 miles) east of mainland Africa, is on "red alert", Rahariveloarimiza told AFP.
Reports of injuries or damage caused by the cyclone's arrival were not immediately available.
Strong winds and heavy winds have been battering Antalaha and Cape Masoala in the country's northeast since Monday. The island's north is particularly exposed to extreme weather systems.
Residents in Enawo's path have been advised in recent days to evacuate low-lying areas, seek shelter and stock up on on food and water.
Rescue teams were deployed across the island ahead of Enawo's arrival.
Madagascar's storm season normally runs from November through February and claims dozens of lives every year.
In 2012, tropical storm Irina and tropical cyclone Giovanna claimed more than 100 lives.
The Indian Ocean island has suffered severe drought and food shortages since 2015, with the southern region the worst affected.