BEIRUT, Lebanon, Oct 15, SPA -- At least one grenade exploded at a downtown Beirut square early Sunday, injuring four people, police said. The grenade was fired from a rifle toward Riad Solh Square in central Beirut and hit a building, the police said. The explosion broke some windows in the building anddamaged two cars, witnesses said. Police and army troopsringed the area and an investigation was under way. Thefour injured, who are all believed to civilians, were takento a hospital for treatment, the Associated Press reported.--SPA www.spa.gov.sa/396297