How many people were killed according to opposition sources before?

Police in the Iranian capital say five people have been killed and more than 300 arrested during the most violent anti-government protests for several months. Earlier, [21C]opposition sources said at least four demonstrators were killed when police shot directly at crowds in central Tehran.
    In Tehran and a number of cities across Iran, the opposition staged massive protests. Security forces took up position early and used tear gas and batons to try to disperse the demonstrations. But in some places they lost control and a number of [23D] police motorcycles and police cars were set on fire. In one area, the protestors even torched a police station. Witnesses reported that then the police began firing directly into the crowd.