Diplomatic relations broken or downgraded in protest against attack on Saudi embassy after execution of Nimr al-Nimr.
Saudi Arabia's regional allies have stepped up diplomatic pressure on Iran, breaking or downgrading relations with the country following an attack on the Saudi embassy in Tehran, which followed executions in the kingdom.
Bahrain announced on Monday that it was closing its embassy in Iran, and called upon Iranian diplomats to leave the country within 48 hours.
Bahrain frequently accuses Iran of being behind protests among its majority Shia population.
Within hours of the announcement, Sudan also said it was cutting off diplomatic relations with Iran "in solidarity with Saudi Arabia".
For its part, the UAE said it was downgrading its ties with Iran, replacing its ambassador with an embassy officer-in-charge.
Saudi Arabia announced on Sunday it was severing diplomatic relations with Iran and urged its allies to follow its move.
The decision came after Iranian protesters attacked its embassy in Tehran, following the kingdom's decision to execute Shia religious figure Nimr al-Nimr along with 46 other mostly Sunni convicts on terrorism charges.
Shia minorities across the Middle East have been demonstrating after Nimr's execution.
Saudi Arabia is adamant Nimr got a fair trial. Many of the men executed had been linked to attacks in Saudi Arabia between 2003 and 2006, blamed on al-Qaeda.
Saudi Arabia further announced on Monday that it was cutting commercial ties with Iran and cancelling all flights to and from Iran, according to foreign media.