Saudi Arabia's new leader-ship confronted its first security crisis on Monday as the US closed all its diplomatic missions in the kingdom for two days and the UK and Australia warned they had “credible reports” that terrorists would soon strike again.

“There are credible reports that terrorists are planning further attacks in the near future,” the UK embassy in Riyadh said in a travel warning on its website. “There is a continuing high threat of terrorism in Saudi Arabia. We continue to believe that terrorists are planning further attacks, including against westerners and places associated with westerners in Saudi Arabia.”