Riyadh: Saudi Arabia on Friday listed the Muslim Brotherhood and two Syrian jihadist groups as terrorist organisations and ordered citizens fighting abroad to return within 15 days or face imprisonment, state TV reported.

The latest move represents a major escalation against the Muslim Brotherhood of deposed Egyptian president Mohammad Mursi and indicates rising concern in Riyadh over the possible return of battle-hardened Saudis extremists from Syria.

Two days ago, Saudi Arabia, the UAE and Bahrain recalled their envoys from Qatar over its support for the Muslim Brotherhood.

In addition to the Brotherhood, Saudi Arabia listed Al Nusra Front, which is Al Qaida’s official Syrian affiliate, and the Islamic State of Iraq and the Levant (Isil), a rogue group fighting in both Syria and Iraq, as terrorist organisations.

It also listed as terrorist groups the Al Houthi rebels fighting in northern Yemen and a little-known internal Shiite group called Hezbollah in the Hijaz.

Saudi and other Gulf states have long been hostile towards the Muslim Brotherhood, fearing that its brand of grass-roots activism and political Islam could undermine their authority.

The order penalises involvement in any of the groups’ activities at home or abroad - including demonstrations - and outlaws the use of “slogans of these organisations”, including in social media.

It also forbids “participation in, calling for, or incitement to fighting in conflict zones in other countries”.

Riyadh is a staunch supporter of the rebels battling to overthrow Syrian President Bashar Al Assad, but has long feared blowback from radical jihadist groups, particularly after a spate of attacks by a local Al Qaida franchise from 2003 to 2006.

King Abdullah last month decreed jail terms of up to 20 years for belonging to “terrorist groups” and fighting abroad.

Similar sentences will be passed on those belonging to “extremist religious and ideological groups, or those classified as terrorist organisations, domestically, regionally and internationally,” state news agency SPA said at the time.

Supporting such groups, adopting their ideology or promoting them “through speech or writing” would also incur prison terms, the decree added.

Rights group Amnesty International sharply criticised last month’s legislation, saying it could be used to suppress peaceful political dissent because the law used an “overly vague definition of terrorism”.

Saudi Arabia set up specialised terrorism courts in 2011 to try dozens of nationals and foreigners accused of belonging to Al Qaida or being involved in a wave of bloody attacks that swept the country from 2003.