At least four persons were killed after a five-storey under-construction building collapsed in South Kolkata’s Metiabruz area on Monday, reported ANI.

Seven other persons are reportedly injured, according to PTI. An unidentified official said that at least 10 persons have been rescued from the site.

According to residents living in the vicinity of the accident, the building had been under construction for the past six months, reported The Indian Express.

Chunks of concrete had reportedly started falling from the building on Sunday night. The debris fell on the shanties adjacent to the building, where residents had been sleeping.

In a post on social media, West Bengal Chief Minister Mamata Banerjee said that Mayor Firhad Hakim, Minister of Fire and Emergency Services Sujit Bose and the commissioner of police, along with officers from the municipal, police, fire and disaster management departments were facilitating the rescue operation.

Banerjee visited the site of the accident and the injured in hospital on Monday.

Banerjee said the building in question had been constructed illegally. “This is a congested area,” she said. “Such areas have developed over the years. A section of promoters, not all, should keep in mind that poor people live around their construction site.”

“I have asked the mayor and he said the building had no legal permission,” Banerjee added. I have asked the authorities to take action against the builder.”

The chief minister said that the administration stands by the families of those who died and the injured.

“I have asked the administration to see about the [reconstruction of] houses which were damaged,” she was quoted as saying by The Indian Express. “Those who are still [trapped] will be rescued soon.”

Hakim, who is also West Bengal’s minister of urban development and municipal affairs, later said that the state government will provide Rs 5 lakh to the families of those who died and Rs one lakh to each injured person.

“It was an illegal building,” he said. “I have asked the police to take action against the builders.”