Security ministry officials will investigate the conduct of its officers at a demonstration at a dump in Pérez Zeledón Sunday.
Police used tear gas on a crowd of residents to open up a roadway for dump trucks. The residents have been protesting for several days because a judge ordered the dump reopened temporarily.
The crowd contained children and an infant as young as two months. In addition at least one woman was in a wheelchair.
One policeman was injured by a rock.
Dump trucks entered the municipal dump after the crowd dispersed.