Thousands of Bahrainis, mainly from the Shia majority, demonstrated near Manama Friday against what they described as "sectarian discrimination" in the Sunni-ruled kingdom.
"No to discrimination," chanted protesters brandishing Bahrain's red-and-white flag as they marched along Budaiya main road, which links Shia villages with the capital, witnesses said.
Ali Salman, chief cleric of the main Shia formation Al-Wefaq was among leaders of the opposition who participated, according to images the group posted online.
They carried posters of prominent opponents jailed over their roles in the short-lived uprising of February 2011, including the Sunni head of the secular Waed party, Ibrahim Sharif, who is serving a five-year sentence.
"Sectarian discrimination is eating into the body of Bahrain in a systematic way applied by authorities," opposition groups said in a statement at the end of the demonstration, referring to the Al-Khalifa dynasty.
The protest was held on the occasion of the UN's International Day for the Elimination of Racial Discrimination.
Bahrain remains deeply divided three years after authorities quashed a Shia-led uprising, with regular protests sparking clashes with police, scores of Shias jailed on "terror" charges and reconciliation talks deadlocked.