Three workers were rescued by the fire brigade after a major blaze engulfed a six-storey school building in Gujarat's Ahmedabad on Friday, officials said.Initially, locals thought three students were trapped on the terrace of the Ankur International School in the Naroda area after the building was engulfed in flames and resultant smoke.However, the school management informed fire brigade officials that the trapped persons were carpenters who were called there for furniture work.The fire, which started at around 11 am, was brought control after one-and-half hour-long operation involving 20 fire trucks, said fire officer Mithun Mistry."The fire started on the ground floor and engulfed some upper floors quickly. The fire has been brought under control. Three workers, who were trapped on the terrace, were rescued by our team and brought down using the main staircase," said Mr Mistry.In view of the coronavirus situation, the school was shut and no student was present in the building, he said."Locals thought three students had got trapped. However, they were workers engaged in furniture work. The fire might have started in the wood polishing chemical which was kept on the ground floor along with plywood sheets. Either an electrical short-circuit or a burning cigarette triggered the fire," said Mr Mistry.