Two Americans jailed in Haiti were charged with conspiracy for participating in a street march that pressed for the return of the country's disbanded army, a Haitian government official said Sunday. Reginald Delva, Haiti's Secretary of State for Public Security, said Jason William Petrie and Steven Parker Shaw were charged Saturday night because of their involvement in last week's march. Authorities say Petrie and Shaw were drivers for a group of ex-soldiers and their young followers who marched in Haiti's capital Friday for the army's return. The demonstration drew hundreds of supporters who donned mismatching military uniforms, including Petrie who wore an army T-shirt and Shaw who wore camouflaged pants. The march that began peacefully turned violent when people began throwing rocks at United Nations peacekeepers and shots were fired outside an old military base. Police locked up 48 other people on a range of charges that included possession of illegal weapons and assault on a police officer. Two other Americans and a Canadian were held for questioning for 24 hours in a police station lobby because they tried to bring medicine to Petrie. Meanwhile, Haitian police have closed three of the old military bases that the leaders of the group had taken over to use as training camps, Delva said.