New Delhi: A powerful cyclone sweeping through southern India has killed at least 21 fishermen and stranded more than 90 others at sea, according to a government official in the state of Kerala.

The storm, Cyclone Ockhi, caught many fishermen off guard over the weekend after it formed quickly in the Arabian Sea and began lashing the Lakshadweep Islands and coastlines in the states of Kerala and Tamil Nadu, reports the New York Times.

On Monday afternoon, the cyclone was about 480 miles southwest of Surat, a city in Gujarat State. The storm was expected to hit the coast near Surat by Tuesday evening, and lose some of its intensity.

The extent of the damage was still unclear on Monday, but Mohammed Faizal, a member of Parliament representing Lakshadweep, said the losses from damage on the islands exceeded $77 million.

The India Meteorological Department classified it as a ‘very severe cyclonic storm,’ a designation for tempests with wind speeds reaching 137 miles an hour.

Cyclones occur in the South Pacific and Indian Ocean; in the Atlantic and Northeast Pacific, such severe storms are called hurricanes.

‘There was no forewarning,’ Sekhar Lukose Kuriakose, of the Kerala State Disaster Management Authority, said by telephone. ‘There was no scientific means of establishing that this was going to become a cyclone.’

But fishermen, saying the government had been slow to notify people of the storm, organized protests on Saturday in Kerala and in Tamil Nadu, blocking roads and pooling resources and boats to try to locate the missing.

Speaking to the families of missing fishermen in Tamil Nadu villages, India’s defense minister, Nirmala Sitharaman, said on Sunday that the country’s navy, air force and coast guard were doing everything possible to try to find the missing fishermen.

‘I speak with folded hands,’ she told the crowd, in which wives of the missing fishermen wept. ‘We have not stopped searching for them.’

Several hundred fishermen have been rescued, the Kerala disaster management agency said. The state has announced compensation payments of about $15,000 each for the families of those who have died.

Mr. Kuriakose said that some of the missing fishermen had already been out at sea days before the cyclone formed.

Before gathering force, the storm killed at least 13 people last week in neighboring Sri Lanka, uprooting trees, forcing schools to shut and disrupting air travel.

The India Meteorological Department said the cyclone was expected to weaken gradually in the next couple of days as it moved north toward the states of Maharashtra and Gujarat.

Heavy rainfall was forecast for the area on Tuesday and officials have advised fishermen in southern Gujarat and northern Maharashtra to stay on shore.