Iraqi lawmakers approved five of the prime minister's candidates for a new cabinet on Tuesday after weeks of delays and chaos at parliament, as thousands of people demonstrated for reforms.

But some MPs, who were barred from attending after chanting for the parliament speaker's removal and disrupting an earlier session, said they would mount a legal challenge.

Iraq has been hit by weeks of political turmoil surrounding Prime Minister Haider al-Abadi's efforts to replace the cabinet of party-affiliated ministers with a government of technocrats.

The crisis comes as Iraqi forces battle to regain more ground from the Islamic State group, and both the United Nations and Washington have warned that it could undermine the fight against the jihadists.

Iraq has also been hit hard by the plummeting price of oil, revenues from which account for the vast majority of government funds.

The proposed cabinet changes have been opposed by powerful political parties that rely on control of ministries for patronage and funds, and parliament has repeatedly failed to vote on a new cabinet list.

Lawmakers approved Abadi's candidates for the ministries of electricity, health, higher education, labour and water resources, MP Sarwa Abdulwahid and two parliamentary officials told AFP.

But they rejected some of Abadi's nominees, and the premier will present additional candidates on Saturday, the sources said.

Earlier in the day, some MPs prevented Abadi from speaking at parliament and threw water bottles in his direction, lawmakers and a parliamentary official who was present at the session said.

Some lawmakers also chanted against parliament speaker Salim al-Juburi, terming him "illegitimate" and saying: "Salim! Out, out!"

The protesting lawmakers were then barred from attending the second session at which the partial cabinet was approved, vowing to file a court case over the issue.

Parliament has repeatedly been hit by chaos in recent weeks, with MPs holding an overnight sit-in at parliament, brawling in the chamber and seeking to sack Juburi, electing an interim replacement who has chaired his own rival sessions.

Abadi called a week ago for parliament to put aside its differences and do its job, but the antics in the legislature have continued.

- Only 'poverty and killing' -

As the latest political turmoil played out in parliament, thousands of protesters demonstrated for reforms nearby, answering a call from powerful Shiite cleric Moqtada al-Sadr to do so.

The demonstrators, many carrying Iraqi flags, marched from Tahrir Square in central Baghdad to an entrance to the heavily fortified Green Zone where the government is headquartered, chanting that politicians "are all thieves".

The government "did not bring the country and Iraqis anything but poverty and killing," said demonstrator Abu Ali al-Zaidi, who travelled from Maysan province in the south for the protest.

"The political quotas and the parties that control everything are the reason for the failure of the government," said Abu Mohammed al-Sudani, a protester from Baghdad who carried an Iraqi flag.

Key government posts have for years been shared out based on political and sectarian quotas, a practice demonstrators want to end.

Ali al-Bahadli, a cleric from the Sadr Movement who was taking part in the demonstration, said: "We want the ministers to be independent, outside the control of the political parties and parliament."

Sadr, the scion of a powerful clerical family who in earlier years raised a rebellion against US-led forces and commanded a feared militia, had called for a mass demonstration in Baghdad on Tuesday to pressure the government to carry out reforms.

He organised a two-week sit-in at entrances to the Green Zone last month, calling it off only after Abadi presented a list of cabinet nominees.

Abadi called in February for "fundamental" change to the cabinet so that it includes "professional and technocratic figures and academics".

That kicked off the latest chapter in a months-long saga of Abadi proposing various reforms that parties and politicians with interests in the existing system have sought to delay or undermine.

US sends warning shot in Iraq via Hellfire missile
Washington (AFP) April 26, 2016 - Before blowing up a jihadist cash hoard in Iraq, the US military warned bystanders of an impending strike by using a Hellfire missile to deliver the wartime equivalent of a doorknock, an official said Tuesday.

It was the first time the Pentagon has conducted a "knock operation" in Iraq and Syria, and the inspiration came from watching the Israel Defense Forces (IDF) pioneer the controversial tactic in Gaza, Major General Peter Gersten said.

The Baghdad-based commander told Pentagon reporters that ahead of the strike on a cash-storage facility on April 5 in Mosul, the military learned that a woman, children and other "non-combatants" also were using the building.

He said the United States aims to avoid civilian casualties, and in this instance decided to warn occupants by exploding a missile just above the roof.

"We went as far as actually to put a Hellfire on top of the building and air burst it so it wouldn't destroy the building, simply knock on the roof to ensure that she and the children were out of the building," he said.

"Then we proceeded with our operations."

Ultimately, the woman died anyway because she ran back just after US forces launched bombs to blow it up.

"Much as we tried to do exactly what we wanted to do and minimize civilian casualties, post-weapons release, she actually ran back into the building," Gersten said. "That's ... very difficult for us to watch."

Gersten said several men had also fled the building. He did not say if they were IS jihadists.

"The men that were in that building, multiple men, literally trampled over her to get out," he said.

The coalition has carried out about 20 strikes on IS cash, blowing up as much as $800 million worth of cash in the process, Gersten said.

Critics of the 20-month-old US-led coalition attacking the IS group in Iraq and Syria say the military is overly cautious in avoiding civilian casualties.

In a move ridiculed by hawkish opponents in the US Congress and privately by some coalition partners, pilots dropped pamphlets before bombing trucks ferrying illicit oil around Syria for the IS group.

The IDF has for years warned occupants of buildings suspected of housing Hamas weapons to get out by "roof knocking."

The technique has drawn sharp criticism. Observers say occupants are sometimes killed in the warning strike, or even run up to their rooftops to see what happened -- only to be killed in the follow-up strike.