The five groups, including the main opposition movement Al-Wefaq, "have decided to suspend their participation in the national dialogue," a joint statement said, a day after the arrest of Khalil Marzooq.

"This decision will be continuously reviewed," it said.

Bahrain's public prosecutor decided on Tuesday to hold Marzooq in custody for 30 days for further investigation.

He was charged with inciting public angers against ruling regime, and using his leadership position in a legally organized political society to incite further opposition with the government policies.

Led by Al-Wefaq, the opposition has been taking part in a national dialogue that began on February 10 aimed at ending the country's political stalemate, while keeping up street protests to call for reform.

Marzooq served as deputy speaker in the 40-member parliament before 18 MPs from Al-Wefaq walked out in February 2011 in protest at violence against demonstrators.

The Manama regime’s human rights record has come under scrutiny over its handling of anti-regime protests that erupted across the country in early 2011.

Bahrainis demanded political reform and a constitutional monarchy, a demand that later changed to an outright call for the ouster of the ruling Al Khalifa family following its brutal crackdown on popular protests.

Manama also called in Saudi-led Arab forces from neighboring states. Scores of people have been killed and hundreds of others arrested in the clampdown.

On September 9, United Nations High Commissioner for Human Rights Navi Pillay told the UN Human Rights Council (HRC) that she was frustrated with reports of human rights violations in Bahrain.

NJF/NJF