Mumbai, Dec 17 (IANS): The death toll in Mumbai's hospital fire shot up to six, while another 147, mostly patients and staff, were rescued from a massive blaze that engulfed the Employees State Insurance Corporation (ESIC) Hospital in Andheri (East) here on Monday, BMC Disaster Control said.

The number of fatalities is likely to increase further as several injured persons have been admitted to various hospitals in serious condition even as the firemen battled the conflagration to bring it under control after three hours.

The fire, caused by a suspected short-circuit, was first noticed in the upper floors of the five-storied building with a glass facade in the MIDC area -- the industrial hub in the north-western suburb -- around 4.15 p.m.

At least 12 fire tenders, 15 water tankers and other specialised equipment were rushed to battle the blaze and those trapped were taken out via ladders from the third and fourth floors as the flames quickly spread horizontally and vertically.

Rescue operations were hampered due to snapping of power supply from the building as a precautionary measure and by 7 p.m the blaze was stated to be "under control", with cooling operations taken up.

Of those rescued, 19 have been admitted in Juhu's Cooper Hospital, including two brought dead, 40 in Holy Spirit Hospital, 44 in Seven Hills Hospital including three dead, 39 were taken to Prabodhankar Thackeray Trauma Care Hospital, Jogeshwari, three in Hiranandani Hospital and two in Siddharth Hospital, for treatment.

Mumbai Mayor Vishwanath Mahadeshwar, who visited the spot along with other senior officials, said the fire would be probed and strict action taken against the guilty if any lapses found.

Thick dark clouds of smoke were seen billowing from long distances in the suburbs and the rescue operations resulted in massive evening peak-hour traffic jams on the busy Andheri thoroughfare connecting north-south and eastern Mumbai.