A Disaster Management Department official said six people, including a married couple, died in different districts of south Bengal, including in Nadia, Purulia and Purba Bardhaman district.

Suburban train services on the Sealdah-Canning line of Eastern Railway's Sealdah division were affected for over an hour, as plantain leaves fell on an overhead electric traction wire during a thunderstorm, an official said.

Train services were affected from 8 pm to 9.15 pm, he said.

A few Kolkata-bound flights from other destinations had to be diverted due to bad weather, Airports Authority of India (AAI) sources said

Inclement weather forced three incoming flights to Kolkata – two from Delhi and one from Bagdogra – to be diverted to other airports, they said.

A Kolkata to Ranchi flight had to return to the parking bay as it could not take off amid thunderstorms, the sources said.

The Met Department has forecast thunderstorms in the region till May 10.

Moderate to heavy rain accompanied with gusty winds were experienced in several districts of south Bengal from Monday afternoon, bringing down temperatures significantly.

The weather office said a cyclonic circulation over south Jharkhand and strong moisture incursion from Bay of Bengal will bring thunderstorms with lightning and gusty winds in various districts of West Bengal.

The maximum temperature in Kolkata was 43 degrees Celsius on April 30, the highest in 50 years, according to the weather office.