Defying curfews, tear gas and live rounds, truckfuls of demonstrators gathered to vent anger over corruption, unemployment and poor services in the biggest challenge yet to Prime Minister Adel Abdel Mahdi.
The demonstrations have left 31 people dead, including two police officers, and more than 1,000 people have been wounded.
'We'll keep going until the government falls'
Baghdad crowds swelled around the ministry for oil and industry, with demonstrators vowing to march to the capital's emblematic Tahrir Square.
"We'll keep going until the government falls," said 22-year-old Ali, an unemployed university graduate.
"I've got nothing but 250 lira ($0.20) in my pocket while government officials have millions," said.
'The destruction of the state'
In his first public address since protests began, the embattled premier made a televised speech early Friday as heavy gunfire rang out across Baghdad.
He described recent events as "the destruction of the state, the entire state", but refrained from directly responding to the protesters' demands.
Monthly stipend for families in need
Meanwhile, Abdel Mahdi defended his government's achievements and pledged a monthly stipend for families in need, while asking for time to implement a reform agenda promised last year.
Anger boils over
The grievances echo those of mass demonstrations in Iraq's south just over a year ago, prompted by a severe water shortage that caused a health crisis.
Since then, southern provinces have accused the central government of failing to address profound infrastructural gaps.
In particular, anger has boiled over at the staggering level of youth unemployment, which is around 25 per cent or doubles the overall rate, according to the World Bank.
'Closure of government offices'
Tensions have been exacerbated by the closure of government offices and calls by firebrand cleric Moqtada al-Sadr for "a general strike".
Sadr was behind major protests in Baghdad in 2016 when his supporters stormed the city's Green Zone, home to some ministries and embassies.
His involvement appears much more limited this time, but if his followers join the protests en masse the rallies will likely balloon even further.
With internet access virtually shut off, demonstrators have struggled to communicate with each other or post footage of the latest clashes.
Approximately 75 per cent of Iraq is "offline" after major network operators "intentionally restricted" access, according to monitor NetBlocks.
The United Nations, European Union and the United Kingdom have all appealed for calm, while rights group Amnesty International slammed the response to protests.
Amnesty's Lynn Maalouf said the internet blackout was a "draconian measure to silence protests away from cameras and the world's eyes".