An explosion at a factory building in Istanbul killed 17 people and injured 40 others Thursday, authorities said. Rescue workers searched the rubble for any survivors. Gov. Muammer Guler ruled out terrorism as a cause, and said an investigation was under way. "Right now, there is nothing linked to terror," said Guler. Businesses in the five-story building included textile makers and an unlicensed fireworks manufacturer, according to local media. Nearby buildings were also damaged. Mehmet Bakar, head of Istanbul's health authority, said the death toll was 17, CNN-Turk television reported. Three of the 40 injured were in serious condition, Bakar said. Part of the factory building in the Davutpasa district of Istanbul collapsed, and a fire broke out on the top floor, NTV said.