In Iran: Elite security team threatens Saudi Arabia

Tehran denies interfering in Arab lands. But the Quds Force, the arm of the Guards that operates abroad, has contributed fighters, weapons and military supplies to back Iran's interests and policies across the region.

Iran's Islamic Revolutionary Guard Corps was quick to condemn the execution of Saudi cleric Sheikh Nimr al-Nimr, stating: "Without a doubt, the hated Saudi regime will pay a price for this shameful act."

For an organization deeply involved in wars in Syria and Iraq this looks no idle threat, at least in the eyes of Sunni Gulf Arab states like Saudi Arabia who say Shi'ite rival Tehran is bent on undermining their security.

The Guard's furious comment is not a call for direct conflict with Riyadh, something neither country wants. But it is a reminder to Gulf Arabs that the IRGC, with connections in Saudi Arabia and elsewhere in the region, has many ways to wage the long cold war between Tehran and its Arab foes.

Tehran denies interfering in Arab lands. But the Quds Force, the arm of the Guards that operates abroad, has contributed fighters, weapons and military supplies to back Iran's interests and policies across the region.

That prospect is worrying for a region where conflicts or political crises from Lebanon and Syria to Yemen, Iraq and Bahrain involve proxies of both powers who are at daggers drawn.

A day after the IRGC issued its statement, which described Saudi rulers as "terrorist fostering, hated and anti-Islam", Riyadh broke off diplomatic relations with Tehran, escalating a contest for power that underpins the region's turmoil.

There is no firm indication that Iran's factionalised leadership has agreed how far it should go to avenge the death of Nimr -- who was one of 47 people executed by Saudi Arabia on Saturday -- and what methods should be used. But whatever steps are authorised, the Guards are likely to be involved, although as orchestrators more than direct participants, experts say.