Tens of thousands of people took part on Friday in a gathering of Bahrain's main Shiite opposition bloc, which is considering withdrawing from a national dialogue, the group said.
The meeting of the Islamic National Accord Association (Al-Wefaq) at Bilad al-Qadim near the capital Manama was attended by "around 50,000 people", the group's Khalil al-Marzuk told AFP.
He is a former MP and head of its delegation at the national dialogue.
In a speech, Al-Wefaq chief Sheikh Ali Salman reiterated its demand for "radical reform centring on a government elected by the people and a parliament with full legislative powers."
Signup to our newsletter and follow us on Facebook and Twitter!
He said the movement was not calling for the fall of the regime in Shiite-majority Bahrain, which is ruled by the Sunni Muslim Al-Khalifa dynasty.
Since the July 2 debut of the national dialogue, which is aimed at forwarding political reforms after Shiite-led protests were crushed in a bloody crackdown in March, Al-Wefaq has called for a government led by the parliamentary majority.
The group won 18 of 40 seats in the most recent parliamentary elections, but its MPs resigned to protest against violence against demonstrators.
Marzuk told AFP the Al-Wefaq delegation at the national dialogue had said it may withdraw from the talks, and would announce its decision on Sunday.
The bloc decided only at the last minute to participate in the dialogue, encouraged by the international community, including the United States, whose Fifth Fleet is based in Bahrain.