The kingdom has also designated the Islamic State in Iraq and the Levant (ISIL), whose militants are involved in the Saudi-backed war to topple the Syrian government, as terrorist organization.

Friday's move appeared to enforce last month's royal decree where Riyadh said it would jail for between three and 20 years any citizen who fought guilty of fighting in conflicts abroad.

Saudi Arabia is one of the biggest financial and political supporters of the war in Syria and according to reports has spent billions of dollars to help Syrian and foreign militants in their war to change the government of Syrian President Bashar al-Assad.

Al-Nusra Front, which fights at the side of the al-Qaeda in Syria, has been one of the most supported groups by Saudi Arabia. Several of the group's commanders have Saudi nationality, according to unofficial reports.

However after nearly three years of deadly war in Syria which has seen hundreds of Saudis joining it, the kingdom's authorities are apparently making some moves against those who participate in foreign wars.

Riyadh also fears the Brotherhood, whose conservative doctrines challenge the Saudi principle of dynastic rule, has tried to build support inside the kingdom since the Arab Spring popular revolutions in the Arab-speaking world.

In Egypt, the Brotherhood, which won every election following the toppling of long-time ruler Hosni Mubarak in 2011, has been driven underground since the army deposed President Mohamed Mursi, a longtime member of the group that also endured repression in the Mubarak era.

The army-backed government in Cairo designated the Brotherhood as a terrorist group in December.

The Brotherhood condemned the move and said the army toppled Morsi by a coup.

SHI/SHI