Analysis: The historically bitter relations between Manama and Tehran have plumbed new depths after Bahrain arrested a "terrorist cell" it says is backed by Iran.
Saudi Arabia's ambassador to Britain has complained of a lack of "mutual respect" between the two countries and warned of "potentially serious repercussions."
Analysis: Moscow and Riyadh's foreign ministers contradict official Saudi policy demanding Assad step down, revealing a potential relaxation of the Saudi position.
Analysis: Saudi Arabia witnessed a spate of deadly attacks this summer, leading to mass arrests. But the kingdom's anti-terrorism strategy has now come under renewed scrutiny.
