With Saudi oil facilities, cities and ships off its coast coming under escalating attacks, the kingdom's top religious authority has called on soldiers to be prepared to defend the country from Iran-backed Houthis.

The strongly worded statement from Grand Mufti Sheikh Saleh al-Fawzan, who traditionally avoids weighing in on politics in a country that holds enormous influence among Muslims worldwide, is a rare message on the ongoing conflict in the Middle East from the kingdom's top religious authority.