Five people were killed and more than 300 injured Saturday when security forces fired gunshots and teargas to disperse a massive pro-reform rally in central Baghdad, according to Iraqi officials.
Baghdad Governor Ali al-Tamimi said four protesters were killed. He added that 320 were injured, including 79 casualties by gunfire.
One policeman was also killed in the violence, according to Baghdad Operations Command, the Iraqi capital's security apparatus.
It said that some protesters were carrying guns and knives.
Thousands of Iraqis loyal to prominent Shia cleric Moqtada al-Sadr gathered in Baghdad's Tahrir Square to demand a revamp of the electoral system ahead of provincial elections in September.
Witnesses said that security forces fired teargas at the demonstrators when they attempted to head to Baghdad's heavily fortified Green Zone, home to government offices and foreign embassies.
Prime Minister Haider al-Abadi promised an investigation into the use of force against protesters.
Earlier in the northern city of Mosul, Iraqi forces killed two would-be Daesh bombers and seized an arms cache in a crackdown on suspected militants in the government-held eastern section of the city, a security official said Saturday.
The area was recently recaptured from the extremist militia as part of a months-long offensive to oust the extremists from Mosul, Iraq's second-biggest city.
"A force from the anti-terrorism service killed the two suicide bombers in a raid before they could target Iraqi troops in the area of Intisar [in eastern Mosul]," Brigadier Younes al-Sherifi, an official in the elite agency, said.
He told dpa that a large cache of arms, including a launch pad for firing rockets containing poison gases and explosives, was seized in another area in eastern Mosul.
"Iraqi forces have since the morning [Saturday] mounted a massive-scale campaign in the liberated districts after the bombings that took place in Mosul," al-Sherifi added.
On Friday, 16 people, including 10 civilians, were killed in three car bombings in different places in eastern Mosul, security and health officials said.
The attacks bear the hallmarks of Daesh, which has previously claimed deadly car bombings in Iraq.
Eastern Mosul was retaken by Iraqi forces, backed by US-led air power, from Daesh last month.
Iraqi forces are bracing themselves for a new offensive aimed at wresting the western part of Mosul from Daesh's control.
The Sunni extremist group seized large chunks of Iraq's territory, including Mosul, in a 2014 blitz.
By Zaid Haris
