Saudi Arabia says it's broken off diplomatic ties with Iran - amid a row over the Saudi execution of a prominent Shia Muslim cleric.

Saudi Foreign Minister Adel al-Jubeir was speaking after demonstrators had stormed the Saudi embassy in Tehran.

Sheikh Nimr al-Nimr and 46 others - including the killer of Irish Journalist Simon Cumbers - were executed on Saturday.

Iranian diplomats have been told they must leave Saudi Arabia within 48 hours.