Protesters in Bahrain have tried to reach the site of a bloody crackdown on demonstrators almost three years ago.
Police used tear gas to stop them from reaching the Pearl Roundabout, which was a focus of protests in 2011.
The protesters have been demanding more rights and an end to discrimination against the majority Shia community by the Sunni royal family.
Since then, police and demonstrators have scuffled almost daily. Thousands of people have been arrested.
The government and opposition have held two rounds of fruitless reconciliation talks, with a third expected soon.
Protesters organised several marches towards the roundabout in the centre of the capital, Manama, but police prevented them from reaching the landmark.
Three years ago, anti-government demonstrations started in the kingdom, which led to the deaths of several protesters.
Several demonstrators were reportedly wounded by security forces during Friday's marches.
The protesters are mostly from poorer, Shia areas in the villages outside the capital.
Protestors have repeatedly used burning tyres and other debris as a tactic to block police vehicles from entering Shia areas.
Three police officers were injured when their vehicle was damaged by an explosion near the village of Dih on Friday evening, interior ministry officials told the AP news agency.
Another two officers were injured near the town of Dair, officials said.
Sunni Muslims are a minority in the country but through the al-Khalifa dynasty have ruled over the Shia Muslim majority for over 200 years.
The small island country is a key US ally in the Gulf and hosts the US Navy's 5th Fleet.
Bahrain is also closely allied with Saudi Arabia, which in 2011 sent troops into the country to help the government quell the uprising.