The U.S. Embassy in Ivory Coast was hit by an errant rocket-propelled grenade on Thursday during protests over a disputed presidential election, the U.S. State Department said. "It does appear that an errant RPG did strike the outer perimeter of the embassy with only slight damage and no injuries," Reuters cited State Department spokesman Mark Toner as saying. Toner said it appeared that the incident occurred as part of cross-fire between two rival groups. Security forces loyal to Ivory Coast incumbent Laurent Gbagbo used live rounds on Thursday to break up protests by supporters of presidential claimant Alassane Ouattara in Abidjan, Ivory Coast's main city, and witnesses said at least four people were killed. The violence came amid a growing crisis over the results of the Nov. 28 election in the world's top cocoa grower.