Nagpur, April 24 : At least three workers were killed in a major fire that broke out in a factory in the Hingna MIDC in Sonegaon-Nipani area of the district, officials said here on Monday. The incident occurred around noon at the Katari Agro Pvt. Ltd. plant and teams of fire-fighters rushed to battle the conflagration. Plumes of dark smoke were seen billowing out of the factory complex that was visible from long distances, said eyewitnesses. At least three workers were charred in the blaze, while another three sustained severe burns and were rushed to nearby hospitals for treatment. According to unconfirmed reports, some more workers were reportedly trapped inside the blazing factory premises and efforts are on to rescue them, though the cause of the fire is not known. Deputy Chief Minister Devendra Fadnavis expressed grief over the tragedy and has directed the Nagpur Collectorate and other agencies to take immediate rescue and relief operations. He has asked the officials to ensure proper treatment to the injured workers and was monitoring the situation from Mumbai. /IANS