The US Secretary of State, Mike Pompeo, called on Iraqi Prime Minister Adel Abdul Mahdi to limit the bloodshed as mass demonstrations demanding political reform continued in Baghdad.
More than 110 people have been killed and 6,000 wounded in just over a week of street demonstrations in central and southern Iraq that have been met by a heavy response from authorities and pro-Iranian militias.
In a call with Mr Abdul Mahdi, Mr Pompeo “lamented the tragic loss of life over the past few days and urged the Iraqi government to exercise maximum restraint", the State Department said over Tuesday night.
Mr Pompeo urged him "to take immediate steps to address the protesters' grievances by enacting reforms and tackling corruption".
Mr Abdul Mahdi released a 13-point plan for jobs, training and welfare for unemployed youths on Tuesday but the move has been regarded by many as too little, too late and is unlikely to ease public anger.
He posted his reforms on social media after a Cabinet meeting despite most Iraqis having been cut off from the internet for days.
In Baghdad, questions have been raised over the extent of Mr Abdul Mahdi'’s authority after police and the military admitted this week that excessive force had been used on protesters.
“Whoever thinks the executive branch, including the commander-in-chief, really are controlling the armed forces should come up with proof,” said Kamran Karadaghi, a former aide to late Iraqi president Jalal Talabani.
This week in a televised address, President Barham Salih called for calm and dialogue.
Demonstrations erupted again overnight in Sadr City, Baghdad’s largest slum and a stronghold of Shiite cleric Moqtada Sadr.
Protesters set fire to tyres outside the municipal council building and courthouse in Mudhaffar Square. Police said that gunfire that targeted the security forces came from a crowd of protesters.
One member of Iraq's Interior Ministry force was killed and four others wounded when they came under fire from unknown assailants in Sadr City, where 15 people died the previous night in riots.
Demonstrators accused security forces of using live ammunition against them.
Journalists on the scene reported seeing protesters killed and wounded by snipers firing from rooftops into crowds.
Iraqi security forces began arresting protesters after nightfall on Tuesday in eastern and north-western parts of Baghdad, police said.
Police carried recent photographs of protesters to identify and arrest them. Iraq's semi-official high commission for human rights said about 500 people had been released from the 800 detained last week.
On Tuesday, Iraq's military called back into service officers and soldiers dismissed for abandoning cities and towns during an ISIS onslaught in 2014.
Parliament, which on Tuesday held its first session since the crisis began, discussed the move and reform plans aimed at pacifying protesters.
A large number of working-class Shiites are taking part in the protests against worsening conditions that the country's poorest people are grappling with due to government mismanagement and rampant corruption.
Life for many in Sadr city has worsened despite the political ascendancy of Shiites after the 2003 US invasion that toppled longtime dictator Saddam Hussein.
Mr Sadr has called on the government to resign and is pushing for internationally-supervised elections to be held.
