KOLKATA: West Bengal chief minister Mamata Banerjee, other ministers, the Kolkata mayor and security officials ripped apart the AMRI Hospital authorities for "callousness", "negligence" and for having blocked rescue efforts during Friday's disastrous fire.

Meanwhile, the AMRI Hospital - known for its high-cost but quality treatment - Friday sought a proper probe to ascertain whether it was an "accident" or a "sabotage".

Coming down heavily on the management of the hospital - co-founded by Emami and Shrachi Groups along with the West Bengal government in 1996 - Banerjee said the hospital staff had even initially prevented the fire fighters from entering the building.

"We will cancel their licence. We will take strict action against them," Banerjee said.

Later in the day, six directors of the hospital were arrested.

Municipal Affairs Minister Firhad Hakim said the fire brigades' big ladder could not enter at first. "The Annexe-1 block has been constructed in a tiny lane. We will conduct an enquiry to find out whether the construction was legal," he said.

Public Works Department Minister Subrata Mukherjee accused the hospital authorities of not making any effort to rescue trapped patients.

"It is horrifying that they made no effort to rescue the trapped patients," he said.

Fire Services Minister Javed Khan said: "There was so much extra-combustible material kept callously that as my men controlled the fire at one spot, the flames reappeared at another area".

"The basement is full of combustible material. It was a space for keeping cars. The way it has been maintained is irresponsible. The departmental engineers have been asked to inspect. The authorities should have followed the norms. If there are lapses we will take steps".

At least 73 people - 70 patients and three staff members - perished in the fire that broke out in the Annexe 1 wing of the hospital at Dhakuria in south Kolkata in the early hours Friday.

The hospital, on the other hand, claimed that it had taken all "safety measures" to prevent such incidents.

"We can confirm that AMRI has followed stringent fire and safety measures and regular fire drills are conducted and all statutory and other compliances were in place," hospital vice president Dr.S Upadhyay said in a statement.

"Once the rescue operation is over, the fire brigade will investigate the cause that led to this unfortunate incident to ascertain whether it was an accident or an act of sabotage," the statement added.