Kolkata: Two days after the massive fire at the AMRI Hospital that killed 93 persons, the exact cause of the inferno remained unknown on Sunday as forensic experts struggled to get evidence.

The deathly silence inside the privately run centrally- airconditioned seven-storey multi-speciality hospital was broken occasionally by the shrill ring of the bell by a fire tender, as the almost deserted premises wore a haunted look with only a few patients remaining.

Smoke was still seen emanating from some parts of the debris and water jet from a fire tender was used to douse it. The fire broke out at the hospital in Dhakuria in the early hours of Friday.

Forensic experts failed to collect any evidence as the basement where the fire started was still under several feet of water.

The experts could not get down to the basement to collect evidence to ascertain the cause of the fire and what materials were stored there, police sources said.

The experts are expected to visit the hospital once again on Monday to carry out their investigations, the sources said, adding that until the basement was drained out, investigation and collection of samples would not be possible.

The basement was flooded by the fire brigade personnel for cooling the overheated basement and the walls and to ensure that no new fire started from any burning ember.

The death toll rose to 93 on Sunday after the death of two persons.

A female patient rescued from the fire-ravaged hospital died at a city nursing home.

Medical director of the Belle Vue Clinic P K Tondon said that 82-year-old Neela Dasgupta, shifted to the nursing home, died around noon. Tondon said she had some heart problems.

Neela's daughter Jaya Dasgupta is the Development and Planning Secretary of the West Bengal government.

Earlier in the day, West Bengal police constable Babulal Bhattacharya died at the AMRI Salt Lake Hospital where he was shifted. He also had some cardiac problems, doctors said. Several people gathered outside the hospital and placed wreaths and lit candles to pay respect to the hapless patients who died inhaling the poisonous smoke from the fire in the basement.

A silent procession was taken out in the evening from in front of the hospital to pay respect to the dead and to protest the deaths of so many patients.

Actors from Tollywood and law school students took part in the procession holding candles from AMRI Hospital to nearby Ramakrishna Mission headquarters in front of which the candles were placed.

A young man, who risked his life to rescue a number of patients from the fire-ravaged hospital, is now fighting for his own life at a city hospital.

On the fateful night, 23-year-old Shankar Maity, a resident of the Panchanantala slum adjacent to the AMRI Hospital's Dhakuria unit, entered the hospital with some neighbours in response to the cries of help by trapped patients.

A group of people from Panchanantala went in a procession to AMRI, Dhakuria and gheraoed some officials in protest against what they described as the "indifference" of the hospital authorities to those who risked their lives in saving others.

"We are not asking for money. All we are asking is that someone from the hospital should visit Shankar," said a processionist.

Even as the annexe building, where the fire occurred, was sealed, there were only 18 patients at the unaffected main building, hospital sources said.

"At present there are only 18 patients at the main building, which has 182-bed capacity," the sources said here.

While no new admission has been made since the Friday tragedy, most of the patients have been shifted to other hospitals in the city.

Hospital sources said that doctors and nurses were attending to the patients in the ICU and wards which were functioning properly.

However, operations were not being carried out as the old block did not have heart care or cathlab facilities.