LUCKNOW, India --A train hit a bus at an unmanned railway crossing in northern India early Thursday, killing at least 31 people and injuring 39 others after a wedding party, an official said. Local administrator Selva Kumar said the bus was filled with about 80 people returning home from the party. The bus stopped at the crossing after its axle broke and was hit by the train, Kumar said. The train dragged the mangled bus more than 1,000 feet (500 meters) before coming to a halt, he said. No passengers on the train were hurt. Kumar said the bride and the groom were traveling in a separate vehicle and were not among the victims. The accident happened near Kanshiramnagar, a village 220 miles (350 kilometers) southwest of Lucknow, the capital of Uttar Pradesh state. "A search operation is under way as there could be more bodies," Kumar said. The injured were taken to a nearby hospital. Train accidents are common in India. The country's railroad network is one of the world's largest and carries more than 14 million passengers each day. Most accidents are blamed on poor maintenance and human error.