Bahrain warned its citizens on Saturday against travel to Iraq and Iran and asked those already there to return "immediately" for their safety, state news agency BNA said.
The Bahrain foreign ministry cited, "unstable regional circumstances, dangerous developments and potential threats," according to BNA.
The warning comes amid simmering tensions between the United States and Iran.
Washington on Wednesday pulled non-emergency staff members from its embassy in the Iraqi capital Baghdad out of apparent concern about perceived threats from neighbouring Iran, to which Iraqi Shia militias are allied.
Earlier on Saturday Exxon evacuated its foreign staff from an Iraqi oilfield.