At least 89 people have been killed in a fire that broke out in a hospital in the eastern Indian city of Calcutta (Kolkata), officials say.Most of the victims were patients who were trapped after the flames spread through the AMRI hospital.The fire started in the multi-storey hospital\'s basement, where flammable materials were stored. Firefighters took five hours to control the blaze.Six board members of the hospital have been arrested.They include hospital co-founders SK Todi and RS Goenka.West Bengal Chief Minister Mamata Banerjee said the licence of the six-storey hospital in Dhakuria in the southern part of the city had been cancelled.She said the fire was an \"unforgivable crime\" and that those responsible would be given the harshest punishment.A Upadhay, a senior vice-president of the AMRI hospital company, told Associated Press there were 160 patients in the 190-bed hospital.A spokesman for Manmohan Singh said the prime minister had \"expressed shock and anguish over the loss of lives\". Chaotic scenesMany of the patients who died suffocated on fumes.A number were rescued. \"We have taken 50 patients to an adjacent hospital. The situation is grim at the moment,\" fire brigade chief Gopal Bhattacharya told Agence France-Presse news agency.The BBC\'s Amitabha Bhattasali in Calcutta says bodies of patients wrapped in white sheets have been brought out by rescue workers.Local people climbed into the hospital compound to rescue patients before fire engines arrived, our correspondent says.The narrow surrounding streets made it difficult for the rescue services to arrive quickly.Subrata Mukherjee, state minister for public health engineering, accused senior hospital officials of running away after the fire broke out: \"It was horrifying that the hospital authorities did not make any effort to rescue trapped patients.\"There were also chaotic scenes when Ms Banerjee arrived.Relatives of patients complained that her convoy had blocked the passage of ambulances in the hospital complex.Police resorted to a baton charge as the crowds moved forward to Ms Banerjee\'s car.\"Stop it. What is this? No baton charge! Have you come here to beat up people?\" the Times of India newspaper quoted Ms Banerjee as telling the officers.Police told AP the six hospital officials arrested were being questioned on charges of culpable homicide and that they had surrendered voluntarily.The fire had spread swiftly from the basement to the upper floors of the private hospital.One rescued patient said: \"The attendants woke me up and dragged me down the stairs. I saw 10-15 patients at the top of the stairs trying to get down.\"Ananya Das, 35, who underwent surgery at the hospital on Thursday, said she was recovering when the fire broke out.\"I managed to walk towards an exit and then climb out of a window. I saw a lot of bodies,\" she said. One relative, Khokon Chakravathi, told AFP: \"My mother is in the intensive care unit. She\'s 70 years old. I don\'t know if she is alive or not.\"Fires in high-rise buildings are fairly common in the city. There have been at least 10 major incidents since 2008.Electrical short circuits have been responsible for most of these fires.