Police in Indonesia's Central Sulawesi province say a bomb that killed seven people and injured 54 in a pork butchery on New Year's Eve was made from a mortar round and ball bearings. They are still questioning a 37-year-old man arrested on the day of the bombing. He had reportedly been seen near the scene of the bombing the previous evening. Police say they do not need to lay charges under Indonesia's counter-terrorism laws until Saturday. They say forensic tests reveal the bomb was made from a mortar round packed into a metal container, along with the ball bearings that caused the injuries to the victims, most of whom were Christians. Police have earlier described the device as a homemade nail bomb.