According to the Fire Department, the blaze started on the third floor of Spice Mall.
After a fire alert around 1.30 p.m., around four fire tenders rushed to the spot, said a senior official.
A fireman at the spot told IANS: "The fire was caused by a spark from the exhaust fan of a kitchen on the third floor. A spark landed on a garbage which caught fire."
According to fire officer Arun Kumar Singh, although it was not a major fire, the smoke entered the four picture halls in the Mall. "We had the halls vacated in time to avoid any casualty."
"Prima facie, the fire was caused by a spark from the exhaust," he added.
Senior Superintendent of Police of Gautam Budhh Nagar Vaibhab Krishna told IANS: "Our staff from Sector 20 and Sector 24 police stations rushed to the spot. The cause of the fire is being investigated. We will take strict action against anyone found negligent."