The decision came as millions of Iranians prepared to visit Iraq for an annual pilgrimage to Shia sites.
Kuwait, meanwhile, has urged its citizens in neighboring Iraq to leave the country. The state-run KUNA news agency also encouraged those hoping to go to Iraq to delay their plans due to the eruption of violent street fighting between rival Shia groups in the country.
The little Arab sheik in the Gulf of Kuwait shares a 254-kilometre border with Iraq.
Dubai’s long-haul carrier Emirates canceled flights to Baghdad on Tuesday amid ongoing unrest in Iraq. The airline said it was “closely monitoring the situation”.
It did not say whether flights would resume before Wednesday.
Protesters loyal to the cleric Muqtada al-Sadr, who resigned on Monday, pulled down the concrete barriers outside the government palace with ropes and broke through the palace gates. Many rushed to the opulent salons and marble halls of the palace, an important meeting place for Iraqi heads of state and foreign dignitaries.
The Iraqi military announced a nationwide curfew and the outgoing prime minister suspended cabinet sessions in response to the violence. Medical officials said dozens of protesters were injured by gunfire and tear gas and physical altercations with riot police.