(AFP) - Cyclone Nisarga ripped roofs off homes in a coastal town near Mumbai Wednesday after officials ordered offices and factories to shut and told people to stay home, reversing a move to ease a coronavirus lockdown in the Indian megacity.

Mumbai and its surrounds are usually sheltered from cyclones -- the last severe storm to hit the city was in 1948 -- but authorities have evacuated at least 100,000 people from flood-prone areas in the states of Maharashtra and Gujarat.

The storm made landfall near the coastal town of Alibag, around 100 kilometres (60 miles) south of Mumbai, on Wednesday afternoon, meteorologists said.

They warned of heavy rainfall -- with winds of 100-110 kilometres per hour (60-70 miles per hour) and gusts of up to 120 kph -- as well as storm surges up to two metres high (6.5 feet).

Those evacuated include nearly 150 coronavirus patients from a recently built field hospital in Mumbai, underscoring the difficulties facing the city ahead of the monsoon season as it struggles to contain the pandemic.

A 45-year-old Alibag resident evacuated from his home near the sea told AFP he could see corrugated roofing flying through the air as Nisarga's powerful winds struck.

"The intensity is very strong and nothing like weather events we've seen before," said Milind Dhodre, a professor who lives in Alibag with his wife and son.

The coastal town is a favoured haunt of Bollywood stars and industrialists, who own holiday homes there.

- 'Do not leave home' -

In Mumbai, police announced fresh restrictions on the city of 18 million people, which was just beginning to emerge from a months-long lockdown, and banned gatherings of four people or more until Thursday afternoon.

"Refrain from venturing out to coast-beaches, promenade, parks and other similar places along the coastline," the police tweeted early Wednesday.

"Do not leave your house for your own safety and well-being," Maharashtra Chief Minister Uddhav Thackeray tweeted late Tuesday, warning of possible disruptions to the power supply due to heavy rainfall.

"Offices, industries and other activities, which have started functioning, will be shut tomorrow and day after," he added.

Slum-dwellers in low-lying areas of Mumbai have been instructed to move to higher ground, with city authorities turning empty schools into temporary shelters.

Inter-state railway services were also disrupted with delays and diversions to ensure that trains would not travel through Mumbai until the cyclone had passed.

Nisarga comes on the heels of Cyclone Amphan, which killed more than 100 people as it ravaged eastern India and Bangladesh last month, flattening villages, destroying farms and leaving millions without electricity.

© Agence France-Presse