Officials say dozens more were injured after protesters loyal to Moqtada al-Sadr stormed the presidential palace, reports BBC.

Violence started after Sadr announced his retirement from politics.

His bloc won most seats in parliament last October, but he has refused to negotiate with Iran-backed Shia groups to form a government, reports BBC.

Street fighting erupted overnight, as fighters exchanged gunfire and tracer rounds illuminated the night sky in some of the worst violence to hit the Iraqi capital in recent years.

Much of the fighting has been concentrated around the city's Green Zone, an area that houses government buildings and foreign embassies.

The violence reportedly forced Dutch Embassy staff to move to the German mission.

Videos shared on social media appeared to show some fighters using heavy weaponry, including rocket-propelled grenades (RPGs).

Iran has closed its borders with Iraq amidst the fighting, and Kuwait has urged its citizens to leave the country immediately, reports BBC.