A major leak of hazardous oleum gas at a chemical unit in Maharashtra’s Palghar district on Monday led to the evacuation of more than 2,600 people, including 1,600 school students, while three persons complained of minor eye irritation, officials said.The leak of oleum (fuming sulphuric acid) occurred around 2 pm at a unit of Bhageria Industries Ltd in the Boisar MIDC area on Mumbai’s outskirts. A dense cloud of white fumes spread rapidly due to strong winds, affecting areas within a five-kilometre radius and triggering panic among residents and workers in the industrial belt.The cause of the leak was not immediately known. Palghar District Collector Dr Indu Rani Jakhar, who is monitoring the situation, said that the disaster management plan was activated immediately. “The leakage occurred from a 2,500-litre capacity oleum day tank. Due to the wind direction, the smoke spread to surrounding areas, impacting a radius of approximately 5 kilometres,” the administration said in a press release.As a precautionary measure, authorities ordered the immediate evacuation of 1,600 students from a local school, Tarapur Vidyamandir. In addition, more than 1,000 workers from Bhageria Industries and neighbouring firms were shifted to safer locations.Teams from the National Disaster Response Force (NDRF), the Bhabha Atomic Research Centre (BARC) and the Fire Brigade were deployed. Officials said the response teams initially faced difficulty in reaching the exact location of the leak.“Due to the high smoke concentration in affected areas, response teams were facing difficulties in reaching the exact location of the gas leak,” the official release noted.Chemical experts and NDRF personnel later located the source and entered the premises using self-contained breathing apparatus (SCBA). Sandbags were placed around the leaking tank to help suppress the fumes.