Manama ordered Tehran's diplomats in the tiny Gulf state "to leave the kingdom within 48 hours," BNA state news agency said on Twitter.
A Bahraini statement said the decision was triggered by "cowardly" attacks on Saudi diplomatic missions in Iran and "increasing flagrant and dangerous meddling" by Tehran in the internal affairs of Gulf and Arab states.
Manama said the attacks on the Saudi missions represent a "very dangerous pattern of sectarian policies that should be confronted... In order to preserve security and stability in the entire region."
Saudi Arabia said Sunday it was severing its ties with Iran after angry crowds set fire to its embassy in Tehran and attacked its consulate in Mashhad a day after Riyadh executed Shiite cleric Nimr al-Nimr.