The Iraqi government has barred non-Iraqi Arab nationals from entering the country ahead of the parliamentary poll on 15 December.
Iraqi and US troops are stepping up security ahead of the poll
An interior ministry official said the move was "part of security procedures", according to Reuters news agency.
The ban was reportedly introduced several days ago, and no date for lifting the restriction has been set.
US and Iraqi forces have said they expect increased rebel violence during the elections.
Non-Iraqi Arab militants have been accused of playing a major role in rebels' attacks since the US-led invasion in 2003.
On Thursday, several non-Iraqi Arabs were prevented from boarding a Royal Jordanian flight to Baghdad, said airport officials in Jordan's capital, Amman.
Royal Jordanian and Iraqi Airways are the only two carriers making regular passenger flights in and out of war-torn Iraq.
The companies need clearance from the US-led coalition troops to land in or take off from Baghdad.
Iraq sealed off its airspace and land borders for several days around general elections in January, and also during October's constitutional referendum.