At least 67 people were injured when a tanker that was transporting flammable contents along a ring-road exploded in Italy's Bologna city on Monday, emergency sources said.The Hazchem transporter exploded when it passed near a car dealership, triggering a series of explosions among cars in a nearby parking lot and leading to the partial collapse of a highway overpass, Efe reported."Highway closed between Bologna Casalecchio and the junction with the A14, Bologna to Taranto, in both directions, due to an accident at kilometer three that involved a tanker," Italian Police said on its official Twitter account. "Side roads also closed, rescue services in progress."Images of the explosion showed two thick plumes of smoke billowing upward from the highway and nearby parked cars, while emergency teams were on hand to respond to the incident.A regional healthcare service officials confirmed that 67 people were being treated for first, second and third-degree burns, and did not rule out the possibility of fatalities.The injured were hospitalized in various health care centers in the area, it said.Two people were in serious condition and sent to hospitals in Parma and Cesena, while another 10 were transferred to Bazzano hospital.Italy's firefighting department shared images on social media accounts showing thick smoke emerging from a vehicle on the highway and a second plume appearing to emerge from cars parked nearby.Video footage released by national police showed the remains of the tanker, ripped wide open by the explosion, resting at the bottom of a collapsed and fire-blackened section of the overpass.