A number of Saudi government websites have been attacked by a hacker group in protest to the arrest of Saudi cleric Sheikh Namer Baqir al-Namer, al-Alam reports.

The hacker group, Mojahedoon al-Ahrar, posted a statement on the websites of local police of the Eastern province, attorney office of Al Bahah Province and city council of Abqaiq city, saying that it was an initiative in revenge of arresting Sheikh al-Namer.

The group also warned the Saudi regime over closure of independent news websites and urged the regime to take more steps to release the political prisoners especially those 18 people arrested recently on the so-called charges of espionage for a foreign country.

The Saudi Interior Ministry said earlier that the suspects are accused of gathering information on vital installations and relaying it to a foreign state.

The group also described the act as a move to defend freedom of speech which could be also considered as a beginning point for collapse of Saudi monarchy.

The group also released a statement and threatened that if the Saudi regime refuses to free Sheikh Namer, they would release some more disclosing information against Saudi government.

Sheikh Namer was attacked, injured and arrested by Saudi security forces en route to his house in Qatif on July 8, 2012.

The cleric had called for the release of all those detained in protests against the Saudi regime, and all the prisoners of conscience. His arrest sparked several protests in Saudi Arabia with thousands of people pouring to the streets and condemning the act.