Kuwait says it is recalling its ambassador to Iran as a regional row over the execution of a Shia cleric in Saudi Arabia deepens.

Saudi Arabia cuts ties with Iran, responding to the storming of its embassy in Tehran in an escalating row between the rival Middle East powers over Riyadh's execution of a Shia Muslim cleric.

US expresses concern that Saudi Arabia's execution of prominent Shia cleric Sheikh Nimr al-Nimr could further exacerbate sectarian rivalry in the Middle East.