Kolkata/IBNS: Two persons were killed and at least seven were injured as an under-construction building, which the administration called "illegal", collapsed in Garden Reach area in Kolkata on Sunday night, media reports said.

The accident took place at Azan Molla Lane in Kolkata's western stretch.

The rescue operation is underway. Several are still trapped under the debris.

Chief Minister Mamata Banerjee, who is yet to recover from her forehead injury, visited the spot this morning and took stock of the situation.

In a shocking admission, Banerjee called the construction as "illegal" and urged her administration to take action against it.

"I came to know from the Mayor that the building had no legal permission. A section of promoters make certain buildings without the permission. I would request the administration to take official action if anyone has worked illegally," the Chief Minister said on spot.

Reportedly, 13 people have so far been rescued.

Kolkata Police Commissioner Vineet Kumar Goyal, Mayor Firhad Hakim and West Bengal Fire and Emergency Services Minister Sujit Bose rushed to the spot at night.

The injured have been admitted to the hospital.

Mayor Firhad Hakim said the government, as he was told by the Chief Minister, will give Rs. 5 lakh to the next of kin of each deceased and Rs. 1 lakh to the injured.

Slamming the ruling dispensation, Leader of Opposition and Bharatiya Janata Party (BJP) MLA, Suvendu Adhikari, called the accident a "TMC-made disaster". 

In a long X post, Adhikari has accused the local councillors, promoters and police of having a collusion with the backing of the ruling Trinamool Congress (TMC), which is headed by Mamata Banerjee.