Save for later Print Download Share LinkedIn Twitter Saudi Arabia's announcement that it had executed dissident Shiite cleric Nimr al-Nimr provoked the expected angry response from Iran, but for Riyadh the image of protestors storming the Saudi embassy in Tehran provided the excuse it needed to swiftly cut diplomatic ties with its Shiite regional rival, and persuade its Gulf Arab allies to follow suit (related). The execution also sparked tensions in the kingdom's own Eastern Province -- home to most of the country's Shiite population, as well as its oil production. Armed men on Tuesday set fire to a bus carrying state Saudi Aramco employees. No one was injured, but the attack set a dangerous precedent. The simultaneous execution of another 43 Sunni extremists, including Al-Qaeda terrorists, also provoked Islamic State, which threatened to eradicate the kingdom's rulers and to destroy prisons holding jihadists. The spat looks set to intensify conflicts throughout the region, with Iran on Thursday accusing Saudi warplanes of damaging its embassy in Yemen (related).