Iraq's parliament is holding an emergency session Saturday to discuss the unrest in Basra that has killed at least 12 people during several days of protest over poor public services, unemployment, and corruption.
The French news agency AFP reports the protests this week were sparked by the hospitalization of some 30,000 people who drank polluted water in Basra.
The Iraqi interior ministry has imposed a curfew in Basra.
An official at Basra's airport said three Katyusha rockets struck the perimeter of the airport Saturday morning, but no injuries were reported. There was no immediate claim of responsibility for the attack, which did not stop planes from taking off and landing.
On Friday, hundreds of protesters in Basra stormed the Iranian consulate in that city and set fire to it, chanting "Iran out, Iran out, free Iraq, free Iraq."
Iraqi Foreign Ministry spokesman Ahmed Mahjoub said, "The targeting of diplomatic missions is unacceptable and detrimental to the interests of Iraq."
U.S. State Department spokeswoman Heather Nauert said in a statement, "Under the Iraqi constitution, the right to peaceful protest and the duty to protect public and private property go hand in hand . . . We call on all parties, including security forces and protesters, to uphold the right of peaceful protest and to protect diplomats and their facilities."
Various sources say that many residents of the predominantly Shi'ite city accuse political parties backed by Iran with interfering in Iraqi politics.
Arab media report that Iran closed its Shalamja border crossing with Iraq after the attack on its consulate and urged its citizens to leave Basra immediately.
The head of Basra security, Gen. Jamil al Shammari, said his men have been trying not to attack protesters, but that it was imperative to protect strategic government installations.
Shammari said the protests have not been peaceful and have been infiltrated by groups trying to cause violence. He said his men were stunned by protesters throwing grenades, setting fire to army vehicles and government buildings, and trying to assassinate people.