A sudden sound of explosion was heard at an elementary school in central Osaka on Tuesday morning. But there were no reports of casualty or major damage to property following the explosion. According to the Osaka City\'s Fire Department, the explosion sound was reported from Kiyoe Elementary School located in southern part of the city at about 10:45 a.m. local time. There was also some smoke seen rising from the school. But all the 200 students and teachers were safely evacuated from classrooms to outside and no one was injured. The explosion occurred at a science resource room at the school, local press reported. Local police and fire department are investigating the cause of the explosion.