The ministry source said that al-Wefaq Secretary General Sheikh Ali Salman would be questioned on Sunday. However, the source declined to provide any details of what the questioning was about.

Wefaq's website confirmed the summon but said the reasons had not been revealed. "It is believed to be part of the political blackmail and revenge against the peaceful opposition that is asking for democracy," it said in a statement.

The deputy leader of al-Wefaq, Khalil al-Marzouq, was arrested in September and is now on trial on alleged charges that include inciting terrorism.

His arrest prompted al-Wefaq to suspend its participation in talks with the regime aimed at ending continued pro-democracy protests in the small Persian Gulf state.

Since mid-February 2011, thousands of pro-democracy protesters have held numerous demonstrations in Bahrain, calling for the Al Khalifa royal family to relinquish power.

Al Khalifa regime with the help of Saudi intervention has cracked down on demonstrators. However, protests later resumed and remain frequent.

Bahraini regime also shut and dismantled an exhibition on anti-regime protests staged by al-Wefaq on Wednesday, saying it violated the law and incited hatred.

Al-Wefaq, advocating non-violent methods, demands a constitutional monarchy with a government chosen from within a democratically elected parliament.

RA/SHI