Bahraini riot police have fired tear gas to disperse hundreds of anti-government protesters to the east of the capital, Manama.
They were attempting to march from the village of Musalla to the Pearl Square roundabout, the focus of protests against the monarchy earlier this year.
A New York Times journalist said the protesters had been shouting “Down with the king”, and some had thrown Molotov cocktails when the police moved in.
No injuries have so far been reported.
The demonstrators had earlier gathered in Musalla to mark the Shia Muslim religious festival of Ashura.
The Gulf kingdom’s Shia majority has been demanding action to tackle economic hardship, the lack of political freedom and employment discrimination in favour of the ruling Sunni minority.
Pearl Square was the centre of protests in February and March, led by the Shia majority, which demanded action to tackle economic hardship, the lack of political freedom, and dominance of the Sunni minority.
The government eventually cracked down violently on the dissent. Officials say at least 24 people were killed, though other accounts put the figure as high as 40.
King Hamad has announced that a panel will be set up to act on the recommendations of an inquiry that found the police had used excessive force, resulting in the deaths, torture and mistreatment of civilians.