Waves lash a shoreline in Mumbai on Monday, as Cyclone Tauktae, packing ferocious winds and threatening a destructive storm, bore down on India, disrupting the country's response to its COVID-19 outbreak. Photo: AFP

At least 21 people were dead and 96 were missing on Tuesday after a monster cyclone slammed into western India, compounding the misery for millions of others who are enduring a ­devastating coronavirus surge.

Hundreds of thousands of people were without power after Cyclone Tauktae, one of a growing number of increasingly severe storms in the Arabian Sea blamed on climate change, hammered the Gujarat coast on Monday evening.

The cyclone packed gusts of up to 185 kilometers per hour, uprooting trees and knocking down power lines and mobile phone towers as it barreled inland while weakening slightly.

One support vessel serving oil rigs that were hit by immense waves off the coast of Mumbai sank and 96 of the 273 people who were on board were missing, the Indian Navy said Tuesday. 

The defense ministry said 177 people were rescued from the vessel, with operations expected to continue throughout the day in "extremely challenging sea conditions."

Elsewhere one fresh casualty was reported on Tuesday, taking the confirmed death toll to at least 21 as savage winds swept through flimsy homes and turned streets into rivers.

Although the cyclone was one of the fiercest to hit the area in decades, better forecasting than in recent years allowed for strong preparations, and more than 200,000 people in danger zones were evacuated from their homes.

Mumbai authorities on Monday closed the airport for several hours and urged people to stay indoors as huge waves battered the city's seafront.

The deadly weather system has hindered India's embattled response to a coronavirus surge that is killing over 4,000 people daily, and pushing the health system to breaking point.

Mumbai shifted on Sunday about 600 COVID-19 patients in field hospitals "to safer locations," while sea levels swelled as high as three meters near the seaside town of Diu.

In Gujarat, all COVID-19 patients in hospitals within five kilometers of the coast were also moved.

But one COVID-19 patient died in the town of Mahuva after he could not be moved in time before the storm hit, doctors said.

Authorities there scrambled to ensure there would be no power cuts in the nearly 400 designated COVID-19 hospitals and 41 oxygen plants in the area.