"Al-Wefaq can confirm that Sheikh Ali Salman has been arrested," the opposition group said in a brief statement.

"He is in detention after a series of illegal measures which comprised summoning him to the office of criminal investigation and bringing him before a public prosecutor," the statement further added.

A number of citizens gathered in front of Sheikh Salman's house after circulating the news about his arrest.

They were holding up pictures of Sheikh Ali Salman and "demanding his immediate release."

In September, al-Wefaq’s deputy leader, Khalil al-Marzouq, was arrested on charges of “inciting protests” against the ruling Al Khalifa family.

The opposition party said the detention was “a clear attack on political activism in Bahrain.”

Scores have been killed, many of them under torture while in custody of the Saudi-backed regime forces, and thousands more detained since the popular uprising began in the Persian Gulf nation in early 2011.

RA/MB