The al-Wefaq National Islamic Society said in a statement on Wednesday that it has boycotted the negotiations for two weeks.

"Al-Wefaq National Islamic Society, and in coordination with the national democratic opposition parties, declares it will temporarily stop attending the dialogue's preparation sessions for two weeks," the statement read.

The statement also cited a recent raid on the house of prominent cleric Ayatollah Sheikh Issa Ahmed Qassim as a reason for the halt.

On May 17, the country’s Saudi-backed security forces attacked the sheikh’s house in the village of Diraz near capital Manama.

Six opposition groups have been holding talks with regime officials since February.

The uprising in Bahrain began in mid-February 2011, when the people, inspired by the popular revolutions that toppled the dictators of Tunisia and Egypt, started holding massive demonstrations.

Bahraini government promptly launched a brutal crackdown on the peaceful protests and called in Saudi-led Arab forces from neighboring states.

Dozens of people have been killed in the crackdown, and the security forces have arrested hundreds, including doctors and nurses accused of treating injured revolutionaries.

A report published by the Bahrain Independent Commission of Inquiry in November 2011 found that the Al Khalifa regime had used excessive force in the crackdown and accused Manama of torturing political activists, politicians, and protesters.

Bahrainis say they will continue holding demonstrations until their demand for the establishment of a democratically elected government is met.