NEW DELHI: At least 13 people including a pregnant woman were killed when an electricity transformer exploded outside a wedding ceremony in western India, police said yesterday. Dozens of guests had assembled for the ceremony outside a family home in the western state of Rajasthan when the transformer exploded, spewing hot oil and metal shards. “Four people died on the spot,” local police superintendent Rameshwar Singh said. “We are ascertaining the cause of the blast.” Singh said several others were being treated for severe burns after the disaster, which triggered protests against the electricity department. Locals said they had raised concerns about the maintenance of the transformer with officials, but nothing had been done. They also said a circuit-breaker failed to work after the blast, exacerbating the disaster as live wires fell onto the crowd late Tuesday in the state capital Jaipur.