The five groups, including the main Shiite Al-Wefaq formation, "have decided to suspend their participation in the national dialogue," a joint statement said, a day after the arrest of Khalil Marzooq on charges of inciting terrorism.
"This decision will be continuously revised," the statement said.
Bahrain's public prosecutor decided yesterday to hold Marzooq in custody for 30 days for further investigation.
He was charged with "inciting and advocating terrorism, and using his leadership position in a legally organised political society to incite crimes," according to a prosecution statement.
Led by Al-Wefaq, the opposition was 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 the influential Shiite opposition bloc Al-Wefaq walked out in February 2011 protesting violence against demonstrators.
In March 20122, security forces in the Sunni-ruled kingdom crushed a month of protests dominated by the country's Shiite majority, which demanded democratic reforms.
