KOLKATA: At least three workers were killed and more than 30 people injured as the chimney of a brick kiln collapsed on them in West Bengal's North 24 Parganas district, police said.

The incident happened on Wednesday evening at Dhaltitah village in Basirhat when the brick kiln was in operation, they said.

"All those injured in the accident are workers of the brick kiln. One person died while undergoing treatment at a nearby hospital, while two bodies were found from under the debris," a police officer said.

"Around 20 people are undergoing treatment at the Basirhat Hospital. Two injured persons were sent to the RG Kar Medical College and Hospital in Kolkata as their condition was very critical," he said.

Among those killed, two were from Faizabad in UP -- Jethuram and Rakesh Kumar.

The other deceased was identified as Hafizul Mondal, a local.

A huge team of police has been deployed for the rescue operation, which is still underway, the officer said.

The cause of the chimney collapse is yet to be ascertained, he said, adding that it will be investigated.