Thousands of Bahrainis took to the streets of Shiite villages around the capital on Friday to demand reforms, with some calling for the ouster of the Sunni-ruled regime, witnesses said.
Muslim clerics, women, and elderly people, responding to calls from the opposition, set off from 10 villages near Manama, they said.
But the protesters stayed away from the centre of Manama city and the former Pearl Square, where deadly confrontations took place last year between protesters and security forces, the witnesses said, as security measures were stepped up.
Most protesters chanted slogans demanding reform, but some called for the "fall of the regime" and others shouted abuse at the Sunni ruling dynasty.
"Down, down, Hamad," they chanted in reference to the ruler of Bahrain, King Hamad bin Issa al-Khalifa.
They also demanded the ouster of Prime Minister Khalifa bin Salman, the king's uncle, who has been in the post for 40 years.
Protesters carried Bahraini flags as well as banners splashed with slogans demanding reform, the witnesses said.
A statement from the Shiite-led opposition said protests will continue until "the oppressive" regime is replaced by "a democratic state."
"Popular movements will continue until the era of the security-based oppressive state is over and is replaced by a civil, democratic state based on freedom, democracy and social justice," said the statement which was also signed by the major Al-Wefaq group.
The opposition also called for an "honest" implementation of recommendations made by an international probe into last year's crackdown on the Shiite-led uprising, and for the release of political prisoners.
On Tuesday the king pledged to press on with political reforms, more than a year after quelling the uprising.
After receiving a report on progress in implementing the probe's recommendations, he said their implementation "reflects Bahrain's commitment to reform in all fields."
He also said the "doors to dialogue were, and remain, open," without, however, referring to an opposition call for "serious" dialogue to end the political deadlock.
On Monday, Bahrain's five main Shiite opposition associations, led by Al-Wefaq, expressed their readiness for dialogue with the authorities.
But they demanded a referendum on the outcome and said the dialogue must include opposition leaders jailed in the wake of last year's crackdown.
Some 35 people were killed in last year's unrest, including five security personnel and five detainees tortured to death, according to an independent commission ordered by the king last June, and tensions have since remained high.