A peaceful demonstration by Bahraini activists turned violent after police stepped in to disperse the demonstrators.
Bahrainis demonstrated in solidarity with political prisoners, calling on the Manama regime to release the inmates.
The protests were mainly held in Buri and Eker regions on Friday.
In Eker, a demonstration turned violent, with clashes breaking out between the protesters and the security forces. Regime forces fired tear gas and rubber bullets to disperse the crowds.
There have been almost daily demonstrations in many parts of Bahrain over the past months.
Demonstrators say sentences issued against the prisoners are unjust.
More than three years since the popular uprising began in Bahrain, the regime crackdown continues unabated.
On September 21, a Bahraini appeals court upheld an earlier ruling that handed five-year imprisonment sentences to nine Shia activists.
Attorneys for the Shia activists, however, insist that the defendants are innocent and were forced to make confessions regarding the charges against them.
Manama has detained hundreds of anti-regime activists as part of its crackdown on protests.
Many of those arrested have been handed down lengthy jail terms.
The media rights group, Reporters without Borders (RSF), had slammed their sentences in April, denouncing Bahraini officials for “cracking down on freedom of information” by arresting journalists and activists and carrying out “sham trials.”
Scores of people have been killed and hundreds of others injured in the crackdown on peaceful rallies.