Police kept their distance, mostly confining themselves to a nearby dirt lot with dozens of SUV police vehicles. The ministry of Interior announced that all roads were open.
The demonstrators from Bahrain's Shia majority say the ruling Sunni minority shuts them out of housing, healthcare and government jobs.
The main Shia opposition bloc Wefaq, which boycotted parliament to protest the clampdown by Sunni security forces, said it would hold talks with the government on Wednesday.
Protesters said their main demand was the resignation of Prime Minister Sheikh Khalifa bin Salman al-Khalifa, who has governed the Gulf Arab state since its independence in 1971.
An uncle of King Hamad bin Isa al-Khalifa, he is thought to own much land and is seen as a symbol of the wealth of the ruling family.
Activists say they also want the release of political prisoners, which the government has promised, and the creation of a new constitution.
Poverty, high unemployment and alleged attempts by the state to grant citizenship to Sunni foreigners to change the demographic balance have intensified discontent among Bahrain's Shi'ites.
Around half of the tiny island kingdom's 1.3 million people are Shia Bahraini, the rest being foreign workers.
