At least forty patients were trapped inside a private hospital in Kolkata at Dhakuria where a fire broke out early Friday morning, police and fire brigade sources said.

The fire which was suspected to have originated in the electrical department in the basement of the AMRI hospital, swiftly spread to the first and second floors, trapping patients, with the fire brigade called in at 4:00 am, the sources said.

Firemen smashed the window panes to rescues patients from the billowing fire and smoke that engulfed the building.

However, at least 40 patients along with some doctors and nurses were still trapped inside the ICU, ICCU, ITU and Critical Care units of the hospital, the sources said.

The firemen were also trying to locate oxygen cylinders stocked on the floors, as the fire could make them explode. Thick smoke was hindering the operations by 25 fire tenders, they said.

Commissioner of Kolkata Police R K Pachnanda and West Bengal Urban Development Minister Firhad Hakim were at the spot. Hakim said that though the firemen were trying, the fire was still not under control.

Personnel of the Disaster Management Group also reached the hospital and were assisting in the operations.