Bahrain is often seen as a bellweather for the Saudi Arabia-dominated Gulf Cooperation Council, which regularly announces sanctions and travel bans targeting countries seen as friendly with Iran.

The Bahraini order and an additional ban on travel to Lebanon marks the latest escalation in a multi-fronted confrontation between Saudi Arabia and Iran which is playing out on political and military battlefields throughout the region, including Lebanon, Syria and Yemen.

Mr Hariri delivered his resignation speech from the Saudi Arabian capital Riyadh, where he claims to have fled for his own safety, citing a foiled assassination attempt by Iran on his way out of Lebanon.