A fire broke out at a mattress factory on Basti Peer Daad Road here on Thursday.It sent thick plumes of smoke into the sky and led to panic among workers and locals.The fire broke out at around 9.15 am when workers were present in the factory. As soon as the blaze was noticed, the workers rushed out of the premises to safety. During this, one of the workers slipped and suffered injuries. He was rushed to hospital.Assistant Divisional Fire Officer Maninder Singh said around 10 fire tenders were pressed into service.A few vehicles were gutted in the fire. The exact cause of the blaze is not immediately known. Officials said they would speak to the factory owner to ascertain the circumstances that led to the fire.The incident caused panic among those living near the factory.Rakesh Agnihotri, a local, said the situation was frightening as the fire appeared to pose a threat to nearby houses.”The administration must take steps to ensure that industrial units are not allowed to operate in residential areas,” he said.