Tens of thousands of Bahrainis have participated in a sit-in in protest at a raid on a senior Shia cleric's home.
The sit-in was called by al-Wefaq, Bahrain's largest opposition political society, after a late night raid on the home of Sheikh Isa Qassim.
Last week's raid provoked anger in the Shia Muslim community.
Sheikh Qassim is the most senior Shia cleric in the Gulf state. Bahrain has a majority Shia population but the ruling royal family is Sunni Muslim.
Shia have long complained of discrimination and formed the largest group when thousands of pro-democracy protesters took over a prominent roundabout in the capital Manama in February 2011.
The protesters were cleared from the roundabout with force and in the ensuing unrest more than 50 people died, hundreds were jailed and thousands lost their jobs.
Virtually all of those affected were Shia Bahrainis.
The government of King Hamad promised reforms in the wake of the violence but critics including Wefaq say that human rights violations and police brutality against protesters continue.
Jasim Husain, a senior al-Wefaq member, told the BBC that the raid on Sheikh Isa Qassim's house had "deeply offended" the Shia community.
"He has a huge number of followers. People were shocked that security forces had raided the home of the most senior religious figure in the country at one o'clock in the morning."
The sheikh was not present at the time of the raid. The security forces were said to have seized documents but no arrests were made.
Friday's sit-in took place in Diraz near Sheikh Qassim's mosque. An observer told the BBC that police had made no attempt to stop protesters entering the town.
Al-Wefaq had called for a peaceful demonstration and there were no reports of violence.
Earlier in the day three Sunni political societies issued a statement denouncing a meeting Sheik Qassim had on Thursday with Rashad Hussain, a senior US state department official.
The societies claimed the meeting, the first ever by a high ranking US official with Sheik Qassim, was evidence that "with this (meeting), the position of the state department and the American government is increasingly exposed in its support for terrorist operations in Bahrain".
The societies and their supporters have long claimed that Sheikh Qassim, acting on Iran's behalf, is responsible for the ongoing unrest in the country.