Iraqi security sources said three Katyusha rockets fired by unknown assailants had hit the perimeter of the airport, although no damage or casualties had been reported.
Months after Iraq declared victory over the Islamic State group, attention has turned from the military battle to the fight for jobs and public services.
Two protesters were wounded, police and hospital sources said, without elaborating after the incident.
The Ministry of Interior launched Sunday a comprehensive field survey to measure the public's satisfaction with the services provided to them through the unified centres located in different areas of the country.
A rare public apology by top transit executives and an assurance from the government that the cause was clear and the fix not complicated have done little to appease the public.