Except for damaging a few huts, Cyclone Fani did not cause much havoc in West Bengal, Chief Minister Mamata Banerjee said as the severe cyclonic storm weakened Saturday morning and headed towards neighbouring Bangladesh.

While flight operations resumed at the Kolkata airport at 9.57 am, train services on the Sealdah and Howrah sections are also getting back to normal.

The Kolkata Port Trust (KoPT) resumed its routine operation Saturday morning at both Haldia and Kolkata docks.

"The entire administration was awake the whole night. We were very worried about the cyclone," Banerjee said.

She had cancelled her election programmes and stayed put at Kharagpur in West Midnapore district to monitor the situation.

"There was not much damage in the state. At least 850 mud houses in the districts were partially damaged, while 12 were destroyed," the chief minister said.

Banerjee said the state government will extend help to people whose houses have been damaged due to the cyclone.

Trees uprooted in different parts of the state due to speedy wind have been removed and the roads cleared for plying of vehicles, she said.

Restoration of electricity snapped in different districts is underway.

"Around 42,000 people have been evacuated by our people who took them to relief shelters. The civic services have been restored in Digha, Mandarmoni, whereas it is work in progress at other places," she said.

The storm weakened on Saturday morning and moved towards Bangladesh. Kolkata witnessed wind speed of 30-40 kmph with moderate to heavy rainfall overnight.

The very severe cyclonic storm weakened into a severe cyclonic storm over the Odisha coast, before moving further north-northeastwards and entering West Bengal through Kharagpur in West Midnapore around 12.30 am Saturday, officials said.

"It has moved to Arambagh in Hooghly and is now in Nadia district from where it will go to Murshidabad district before entering Bangladesh. It is likely to continue to move north-northeastwards and weaken further over the next six hours," Deputy Director General of the Regional Meteorological Centre here, Sanjib Bandyopadhyay, told PTI.

Kolkata Mayor Firhad Hakim along with senior engineers of the civic body and local councillors was on a night-long vigil in and around the city to keep a tab on the situation.

"We had made arrangements to act on an emergency basis had Fani hit the city. But thank god, nothing major has happened," Hakim told PTI.

Much to the glee of passengers, flight operations which were suspended from 3 pm on Friday resumed at the Kolkata airport at 9.57 am Saturday, an Airports Authority of India (AAI) official said.

Air India was the first airline to start operating out of Kolkata airport, the official said, adding a GoAir flight from Delhi was the first flight to land in Kolkata at 10.10 am.

The AAI official said airlines had refunded fares of cancelled flights to the passengers and took care of them.

Very few passengers had stayed back at the airport on Friday, the official said.

Out of an average 224 daily flights, only 110 flights operated on Friday, the official said.

Train services on the Sealdah and Howrah sections are also getting back to normal, officials said.

The ferry services on river Hooghly, however, were yet to resume.

Five persons were injured when a portion of the roof of a hutment collapsed on Friday night in central Kolkata's Beniatola Lane, police said.

All of them were released after treatment.

Kolkata Port Trust chairman Vinit Kumar said there had been no damages to the port infrastructure.

"Operations at both Kolkata and Haldia docks have resumed since morning," he said.

Meanwhile, Governor Keshari Nath Tripathi visited Kakdwip subdivision of South 24 Parganas district to review the situation after the area was affected by the cyclone.

Tripathi met local administration officials and interacted with people to ascertain the impact of Fani and the relief work.

"He also went to a multipurpose cyclone shelter in Madhusudanpur where people had taken shelter the preceding night," a source at the Raj Bhawan said.

The Governor will be visiting cyclone affected areas of West Midnapur district on Sunday, he said.