Bahrain ordered its citizens in Lebanon to “leave immediately” Sunday after the country's prime minister resigned in a sudden televised address, citing Iranian meddling in Lebanese and regional affairs.

Bahrain's Foreign Ministry said citizens were banned from traveling to Lebanon, as well.

Bahrain is a bellwether nation for the Saudi Arabia-dominated Gulf Cooperation Council and often the first to announce sanctions and travel bans, usually targeting countries seen as close to Iran.

GCC member states banned travel to Lebanon in 2016 after Lebanon's foreign minister refused to condemn mob attacks on Saudi diplomatic missions in Iran.

Lebanese Prime Minister Saad Hariri upended his country's politics with his surprise resignation Saturday.

He delivered it in a televised address from Saudi Arabia, leading his supporters and detractors in Lebanon to speculate he received orders to step down from Saudi Arabia, widely seen as his patron. He is not believed to have returned to Lebanon.

Hariri became prime minister in late 2016 in a coalition government that included the militant group Hezbollah, one of Saudi Arabia's chief detractors in the region.

He could not have formed a government without the group, which operates its own militia freely in Lebanon.

Hezbollah and its allies have been given veto power in Lebanese politics since Hezbollah forces seized the streets of Beirut in brief clashes in 2008.

Their political bloc controls the largest shares of seats in Lebanon's parliament.

Hezbollah was founded with Iranian support in 1982 to resist the Israeli invasion of Lebanon and has since emerged as a regional power in its own right.

It is fighting alongside Iranian advisers and militias in the civil war in neighboring Syria, providing crucial support to Syrian President Bashar Assad's forces as a crackdown on anti-government demonstrations morphed into full-fledged war.

Dozens of rebel factions in Syria are or have been backed by Turkey, Saudi Arabia, and Saudi Arabia's gulf allies.

Lebanon, once one of the key flashpoints of the Saudi-Iran rivalry, officially declared itself neutral with respect to the Syrian war. But Hezbollah fighters poured into Syria, angering Saudi Arabia.

Assad and his Iranian-supported allies are now firmly in command of the war in Syria, in a humiliation to Saudi Arabia and the Gulf.