Activists said violence erupted on Saturday after Saudi-backed Bahraini troops attacked the protesters who were attending funeral processions for four demonstrators killed by regime forces on Wednesday.
Thousands of people turned out for the processions, which turned into demonstrations after mourners shouted anti-regime slogans.
Activists and rights groups say at least 10 protesters have been killed in Bahrain so far this year.
Bahrain has been the scene of anti-regime protests since mid-February 2011, which was immediately met with a brutal crackdown by the ruling Al Khalifa family.
Saudi-backed Bahraini forces continue their violent crackdowns on the demonstrations in the country.