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Iranian women gather during a demonstration against the execution of prominent Shiite Muslim cleric Nimr al-Nimr (portrait) by Saudi authorities, at Imam Hossein Square in the capital Tehran on January 4, 2016. Tensions between Iran and its Sunni Arab neighbours reached new heights as Saudi Arabia and Gulf allies cut or downgraded diplomatic ties with Tehran in a row over the execution of a Shiite cleric. AFP PHOTO / ATTA KENARE / AFP / ATTA KENARE        (Photo credit should read ATTA KENARE/AFP/Getty Images)
Iranian women gather during a demonstration against the execution of prominent Shiite Muslim cleric Nimr al-Nimr (portrait) by Saudi authorities, at Imam Hossein Square in the capital Tehran on January 4, 2016. Tensions between Iran and its Sunni Arab neighbours reached new heights as Saudi Arabia and Gulf allies cut or downgraded diplomatic ties with Tehran in a row over the execution of a Shiite cleric. AFP PHOTO / ATTA KENARE / AFP / ATTA KENARE        (Photo credit should read ATTA KENARE/AFP/Getty Images)

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Saudi Arabia and Iran's tumultuous history

As Saudi Arabia and Iran ramp up their diplomatic face-off, CNN's Lynda Kinkade looks at the historically turbulent relationship between the two countries.

Saudi Arabia and Iran's tumultuous history

As Saudi Arabia and Iran ramp up their diplomatic face-off, CNN's Lynda Kinkade looks at the historically turbulent relationship between the two countries.