Sparks are flying above the powder keg that is the Middle East as Saudi Arabia announces that it has cut diplomatic ties with Iran.

On Saturday Saudi Arabia held a mass execution of 47 prisoners, including prominent Shi'ite cleric Sheikh Nimr al-Nimr. Iranians overran Saudi Arabia's embassy in Tehran as they protested Sheikh al-Nimr's death, eventually setting it on fire.

Late Sunday, Saudi Arabia's foreign minister Adel bin Ahmed Al-Jubeir demanded all Iranian diplomats leave his country within 48 hours. Saudi Arabia officially severed any ties with its powerful rival for oil and gas export dollars.

Reuters reported that Iran has said there will be "divine vengeance" against the Saudis for the cleric's death. Nearby allies joined in:

Strong rhetoric from Tehran was matched by Iran's Shi'ite allies across the region, with Sayyed Hassan Nasrallah, the head of Lebanese militia Hezbollah, describing the execution as "a message of blood". Moqtada al-Sadr, an Iraqi Shi'ite cleric, called for angry protests.

There have been waxing and waning sectarian tensions between the nations for decades, but this comes at a particularly perilous time for the region, with Russia and western nations currently involved in operations against ISIS, which has entrenched itself in parts of Iraq and Syria.

h/t Reuters/Bloomberg/CNN