Bahrain leading opposition society Al Wefaq has suspended its participation in the Kingdom's "national dialogue" after a wave of raids and detentions by security forces.
The Dialogue began in February, with the involvement of pro-regime and opposition groups, as well as Government ministers and MPs, in an attempt to resolve the issues of reform and justice highlighted by mass protests from February 2011.
However, other opposition factions have denounced the Dialogue as little more than a token gesture, and the discussions have made little progress.
"Al-Wefaq, in collaboration with other opposition forces, has decided to suspend its participation in the national dialogue preparatory sessions for two weeks," the opposition society said.
Al Wefaq claimed the arrests of "hundreds of citizens" and raids of homes, including that of Bahrain's leading Shia cleric Sheikh Isa Qassim last week.
The society said the move was also a protest against "unfair verdicts against prisoners of conscience".
Leading activists have been given sentences up to life, such as Abdulhadi Alkhawaja, the founder of the Bahrain Center for Human Rights. Nabeel Rajab, the head of the BCHR, has been in prison since last July, serving a three-year sentence, while Alkhawaja's daughter Zainab has been given a series of three-month terms.
On Monday, a Bahraini court sentenced nine men to terms between 10 and 15 years after convicting them of forming a "terrorist" group.