five people were kiled in northeastern bulgaria following a gas explosion on a derailed tanker train early saturday, firefighters in bulgaria said. officials said at least 23 people were injured, many with severe burns. the chief of the bulgarian firefighting department nikolay nikolov, said at least 20 buildings in the village of hitrino were destroyed when containers of liquefied petroleum gas exploded at 5:40 a.m. local time (0340 gmt). the immediate surroundings of the disaster site were evacuated, and the cause of the disaster was unclear, nikolov said. two tank cars, carrying propane-butane and propylene, derailed at the station in hitrino, hit electricity lines and exploded, police officials said. the motor driver survived and has been questioned, police said. video footage from the scene showed many houses in the village of 800 on fire and ambulances taking the injured to hospitals. prime minister boiko borisov, who arrived at the site of the blast, urged citizens to donate blood to address shortages at nearby hospitals. the train had been traveling from the bulgarian black sea port city of burgas to the danubian city of ruse. the accident occurred in hitrino, a town of around 800 people, is located in bulgaria's north-eastern shumen province, about 60 miles (100km) from the black sea.