Iraqi forces have been forced to pause the offensive on the Isis stronghold of Mosul by the “catastrophic” rate of civilian casualties reported in the city.

The US-led coalition is investigating allegations its air strikes killed more than 130 men, women and children as they sheltered in their homes in the western district of al-Jadida.

Central Command confirmed it carried out bombings that “correspond to allegations of civilian casualties” for the first time on Saturday, but insisted the strikes hit Isis fighters and equipment.

Local residents said at least 137 civilians had been killed in a cluster of homes hit on 13 and 17 March, which some reported had previously been used as a sniper position by Isis.

Journalists saw children and a pregnant woman among at least 50 bodies recovered from the rubble, with limbs and shoes protruding from destroyed houses.

Iraqi government forces suspended their six-month advance on Saturday amid growing international pressure over the incident and numerous other allegations of civilian deaths.

“The recent high death toll among civilians inside the Old City forced us to halt operations to review our plans,” a Federal Police spokesman said. “It’s a time for weighing new offensive plans and tactics. No combat operations are to go on.”

Iraqi forces launch push to retake western Mosul from IS

A spokesperson for the US-led Operation Inherent Resolve said an investigation had been opened to determine the “validity” of claims over its strikes and insisted they corresponded with international law.

“The coalition respects human life, which is why we are assisting our Iraqi partner forces in their effort to liberate their lands from Isis brutality,” he added.

“Our goal has always been for zero civilian casualties, but the coalition will not abandon our commitment to our Iraqi partners because of Isis’ inhuman tactics terrorising civilians, using human shields, and fighting from protected sites such as schools, hospitals, religious sites and civilian neighbourhoods.”

The Pentagon previously announced four strikes near Mosul on 17 March, saying they destroyed 25 fighting positions, 56 vehicles plus a suicide car bomb.

The US’ official civilian death toll from the air campaign against Isis in Syria and Iraq stands at 220, although monitors say the real total is far higher. Not-for-profit group Airwars warned this week of “record” deaths as bombing reached unprecedented intensity.

It said the number of reported civilian casualties in coalition strikes has hit 1,000, with allegations accelerating under Donald Trump to suggest “possible key changes in the US rules of engagement that are placing civilians at greater risk”.

In pictures: Mosul offensive Show all 40 1 /40 In pictures: Mosul offensive In pictures: Mosul offensive A doctor carries an Iraqi newborn baby at a hospital in Mosul, Iraq July 18, 2017. Reuters In pictures: Mosul offensive Iraqi girls play at a yard of a school in Mosul, Iraq July 18, 2017alal Reuters In pictures: Mosul offensive A woman on crutches who is a relative of men accused of being Islamic State militants is seen at a camp in Bartella, east of Mosul, Iraq July 15, 2017. Picture taken July 15, 2017. Reuters In pictures: Mosul offensive A displaced girl, who fled from home carries a doll at Hamam al-Alil camp south of Mosul, Iraq July 13, 2017. Reuters In pictures: Mosul offensive Iraqi federal police members and civilians celebrate in the Old City of Mosul on 9 July 2017 after the government's announcement of the "liberation" of the embattled city. Iraqi Prime Minister Haider al-Abadi's office said he was in "liberated" Mosul to congratulate "the heroic fighters and the Iraqi people on the achievement of the major victory" AFP/Getty Images In pictures: Mosul offensive A picture taken on 9 July 2017, shows a general view of the destruction in Mosul's Old City. Iraq will announce imminently a final victory in the nearly nine-month offensive to retake Mosul from jihadists, a US general said Saturday, as celebrations broke out among police forces in the city. AFP In pictures: Mosul offensive Members of the Iraqi federal police raise the victory gesture as they ride on a humvee while advancing through the Old City of Mosul on 28 June 2017, as the offensive continues to retake the last district held by Islamic State (IS) group fighters. AFP/Getty Images In pictures: Mosul offensive Smoke billows as Iraqi forces advance through the Old City of Mosul on 26 June 2017, during the ongoing offensive to retake the last district held by the Islamic State (IS) group. AFP/Getty Images In pictures: Mosul offensive An Iraqi man wearing the green scarf of the Shi'ite faith kisses an Iraqi Army soldier on safely reaching the Iraqi forces position as Iraqi civilians flee the Old City of west Mosul where heavy fighting continues on 23 June 2017. Iraqi forces continue to encounter stiff resistance with improvised explosive devices, car bombs, heavy mortar fire and snipers hampering their advance. Getty Images In pictures: Mosul offensive A picture taken from the inside of an Iraqi forces armoured vehicle shows residents walking through a damaged street as troops advance towards Mosul's Old City on 18 June 2017, during the ongoing offensive to retake the last district still held by the Islamic State (IS) group. Military commanders told AFP the assault had begun at dawn after overnight air strikes by the US-led coalition backing Iraqi forces. They said the jihadists were putting up fierce resistance. AFP/Getty Images In pictures: Mosul offensive Iraqi Army soldiers advance in a destroyed street after an Iraqi forces airstrike targeted an Islamic State sniper position 17 June 2017 in al-Shifa, the last district of west Mosul under Islamic State control. IS snipers, as well as car and suicide bomb attacks continue to hinder the Iraqi forces efforts to retake the final district. A series of airstrikes by Iraqi helicopter gunships attempted to hit multiple Islamic State sniper positions in al-Shifa. Getty Images In pictures: Mosul offensive An Iraqi soldier frisks a displaced Iraqi man at a temporary camp in the compound of the closed Nineveh International Hotel in Mosul on 16 June 2017 which was recovered by Iraqi troops from Islamic State group fighters earlier in the year. A screening centre set up in the compound's fairgrounds sees a constant stream of Iraqis fleeing the battle for Mosul, awaiting their turn to be checked by the Iraqi forces who are searching for suspected Islamic State (IS) group members. The small fairground lies at the end of a pontoon bridge across the Tigris recently opened to civilians that is the only physical link between the two banks of the river. AFP/Getty Images In pictures: Mosul offensive Iraqis staying at the al-Khazir camp swim in a river near the camp for internally displaced people, located between Arbil and Mosul on 11 June 2017. AFP/Getty Images In pictures: Mosul offensive Iraqi government forces drive on a road leading to Tal Afar on 9 June 2017, during ongoing battles to retake the city from Islamic State (IS) group fighters. AFP/Getty Images In pictures: Mosul offensive An Iraqi policeman carries a poster bearing an image of Mosul's iconic leaning minaret, known as the "Hadba" (Hunchback), on 22 June 2017. AFP/Getty Images In pictures: Mosul offensive Iraqis stand in line to receive food aid in western Mosul's Zanjili neighbourhood on 7 June 2017, during ongoing battles as Iraqi forces try to retake the city from Islamic State (IS) group fighters. Living conditions in Mosul have again deteriorated since the start of the Iraqi government's offensive on the city in October in which they retook a large part of the west of the city. AFP/Getty Images In pictures: Mosul offensive Displaced Iraqis carry lightbulbs and sacks as they evacuate from western Mosul's Zanjili neighbourhood as government forces advance in the area during their ongoing battle against Islamic State (IS) group fighters on 13 May 2017 AFP/Getty Images In pictures: Mosul offensive A member of the Iraqi Counter-Terrorism Service (CTS) flashes the victory gesture as he patrols in western Mosul's al-Islah al-Zaraye neighbourhood on 13 May 2017 AFP/Getty Images In pictures: Mosul offensive Iraqi army soldiers from the 9th armoured division on a truck flash the sign of victory as they drive back from Mosul to the town of Qaraqosh (also known as Hamdaniya) Getty In pictures: Mosul offensive Members of Iraqi forces flash the sign of victory on their vehicle as they advance towards Hammam al-Alil area south of Mosul Getty In pictures: Mosul offensive A member of Iraqi security forces gestures in Hammam al-Alil, south of Mosul, Iraq Reuters In pictures: Mosul offensive Iraqi children, one flashing the sign of victory, greet Iraqi army's soldiers from the 9th armoured division in the area of Ali Rash, adjacent to the eastern Al-Intissar neighbourhood of Mosul Getty In pictures: Mosul offensive Peshmerga forces look at a tunnel used by Islamic State militants near the town of Bashiqa, east of Mosul, during an operation to attack Islamic State militants in Mosul, Iraq Reuters In pictures: Mosul offensive An Iraqi soldier takes a photograph with his phone as his comrade stands next to a detained man, whom the Iraqi army soldiers accused of being an Islamic State fighter, who was fleeing with his family in the Intisar disrict of eastern Mosul, Iraq Reuters In pictures: Mosul offensive Iranian Kurdish female members of the Freedom Party of Kurdistan (PAK) hold a position in an area near the town of Bashiqa, some 25 kilometres north east of Mosul Getty In pictures: Mosul offensive Iraqi families, who fled their homes in Hamam al-Alil, gather on the outskirts of their town Getty In pictures: Mosul offensive Displaced people walk past a checkpoint near Qayara, south of Mosul, Iraq AP In pictures: Mosul offensive Iraqi families who were displaced by the ongoing operation by Iraqi forces against jihadists of the Islamic State group to retake the city of Mosul, are seen gathering in an area near Qayyarah In pictures: Mosul offensive A boy who just fled Abu Jarbuah village is seen with his family at a Kurdish Peshmerga position between two front lines near Bashiqa, east of Mosul, Iraq Reuters In pictures: Mosul offensive An Iraqi child eats a pomegranate upon the arrival of Iraqi forces in the village of Umm Mahahir, south of Mosul Getty In pictures: Mosul offensive People who just fled Abu Jarbuah village sit as they eat at a Kurdish Peshmerga position between two front lines near Bashiqa, east of Mosul, Iraq Reuters In pictures: Mosul offensive A couple who just fled Abu Jarbuah village are escorted by Kurdish Peshmerga soldiers Reuters In pictures: Mosul offensive Women carry a boy over a wall as civilians flee their houses in the village of Tob Zawa, Iraq AP In pictures: Mosul offensive An Iraqi soldier and a civilian ride a motorbike as smoke rises behind them, on the road between Qayyarah and Mosul Getty In pictures: Mosul offensive A member of Iraqi forces, wearing a skull mask, waits at a checkpoint for people fleeing the main hub city of Mosul Getty In pictures: Mosul offensive An Iraqi soldier sits at a checkpoint in an area near Qayyarah Getty In pictures: Mosul offensive Iraqi men prepare food portions for Iraqi forces deployed in areas south of Mosul Getty In pictures: Mosul offensive Iraqi forces celebrate upon the arrival of vehicles bringing food to them Getty In pictures: Mosul offensive Iraqi childen smoke cigarettes upon the arrival of Iraqi forces in the village of Umm Mahahir, south of Mosul Getty In pictures: Mosul offensive A member of Iraqi forces distributes drinks to children in the village of Umm Mahahir, south of Mosul Getty

The President issued an executive order demanding a new plan to defeat Isis from his military, which arrived on his desk in February but has not been detailed in public.

The UN said it was “profoundly concerned” by the reports emerging from al-Jadida, which it described as “densely populated”.

“We are stunned by this terrible loss of life and wish to express our deepest condolences to the many families who have reportedly been impacted by this tragedy,” said Lise Grande, the Humanitarian Coordinator for Iraq.

“Nothing in this conflict is more important than protecting civilians.

“International humanitarian law is clear. Parties to the conflict – all parties – are obliged to do everything possible to protect civilians.

“This means that combatants cannot use people as human shields and cannot imperil lives through indiscriminate use of firepower.”

Senior Iraqi politicians also expressed concern, with speaker Salim al-Jabouri saying that although MPs recognised the responsibility shouldered by government forces, they must “spare no effort to save the civilians”.

Iraqis displaced by fighting flee to the Al-Sumoud neighbourhood of Mosul on March 22, 2017 (AFP/Getty)

Vice President Osama al-Nujaifi, himself from Mosul, described the al-Jadida strikes as a “humanitarian catastrophe”, calling for an emergency parliamentary session and an immediate investigation into the incident.

Isis has been fortifying Mosul, where leader Abu Bakr al-Baghdadi declared his Islamic State in 2014, for almost four years and its militants are deploying suicide car bombs, mines, booby traps, ambushes, mortars and drones to defend their last city stronghold in Iraq.

Faced with their toughest battle yet, Iraqi and coalition forces have increasingly turned to air strikes and artillery to clear and hold territory in Mosul’s densely-populated western districts.

Progress has faltered in the last two weeks as fighting enters the narrow alleys of the Old City, where thousands of civilians have been fleeing every day.

An army statement published in the al-Sabah state newspaper said that future operations would be carried out by ground troops highly trained for urban combat.

“Our heroic forces are committed to the rules of engagement which ensure protection of civilians” it added.