The British government is in “deep denial” over its contribution to the high civilian death toll in the campaign to oust Isis from its self-declared capital of Raqqa, Amnesty International said on Monday.

The UK was a key partner in the US-led coalition’s offensive to liberate the Syrian city from Isis this time last year, following a brutal four-month battle spearheaded by Kurdish forces on the ground and devastating air power from above. But that victory came at a devastating cost for Raqqa’s inhabitants.

More than 1,500 civilians were killed in coalition air and artillery attacks between June and October 2017, according to Airwars, a UK-based independent investigative group that tracks civilian casualties in the fight against Isis.

The US, which accounted for around 90 per cent of the air strikes on Raqqa, has so far admitted responsibility for the deaths of around 100 civilians in the city. Hundreds of casualties were also caused by mines and IEDs left by Isis.

The RAF carried out some 216 airstrikes in and around the city during the offensive, but the Ministry of Defence has denied that any civilians were harmed as a result. It is now under renewed pressure to reevaluate that claim, and carry out further investigations into its contribution to the civilian death toll.

“It stretches credibility to breaking point to believe that the MoD’s part in the massive aerial bombardment of Raqqa didn’t cause even one civilian death,” Oliver Sprague, Amnesty International UK’s military expert, told The Independent.

“Rather than focusing on the devastating impacts of this joint bombing operation, the MoD has sought to undermine the credibility of Amnesty when we’ve published evidence detailing coalition airstrikes that killed civilians,” he added.

Most of Raqqa still lies in ruins today. Around 80 percent of the city was destroyed in the fighting, according to the UN, and little progress has been made in rebuilding vital infrastructure.

It stretches credibility to breaking point to believe that the MoD’s part in the massive aerial bombardment of Raqqa didn’t cause even one civilian death Oliver Sprague, Amnesty’s UK military expert

The UK has been largely shielded from criticism over its part in the Raqqa campaign due its junior role in comparison to the US. But Amnesty International is not alone in casting doubt on the MoD’s claim that it caused no civilian casualties in the city.

In written evidence submitted to a Defence Select Committee hearing on UK military operations in Raqqa and Mosul in May, Airwars said regular use by the RAF of the Paveway IV, a 500lb bomb, would likely have caused civilian deaths in the densely populated city.

“Given the intensity of the strikes and the nature of the city and the number of population in Raqqa, it is a statistical impossibility that no civilians were harmed in these airstrikes,” Abdulwahab Tahhan, Syria researcher at Airwars, told The Independent.

The use of human shields by Isis – documented by several rights groups – also contributed to the high civilian toll.

"War of Annihilation" – devastating toll on civilians in Raqqa, Syria Show all 20 1 /20 "War of Annihilation" – devastating toll on civilians in Raqqa, Syria "War of Annihilation" – devastating toll on civilians in Raqqa, Syria A child injured by an IED explosion in Raqqa Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Children riding a bicycle among destroyed buildings in Raqqa Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Entire neighbourhoods in Raqqa are damaged beyond repair Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Satellite image showing the house where seven members of the Badran family were killed in a Coalition strike on 18 July 2017, before the strike CNES/Airbus DS "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Satellite image showing the house where seven members of the Badran family were killed in a Coalition strike on 18 July 2017, after the strike CNES/Airbus DS "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Members of the Badran family killed in three separate Coalition air strike on 18 July and 20 August 2017 in Raqqa Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria The city of Raqqa in northern Syria has become hardly recognizable to those who try to return after months battle between US-backed forces and the Islamic State terrorist group for control of it. The city has no running water or electricity and homes, business and public squares are mere rubble and debris Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Satellite image showing the houses where 16 members of the Fayad family and neighbours were killed in Coalition strikes on 12 October 2017, before the strike CNES/Airbus DS "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Satellite image showing the houses where 16 members of the Fayad family and neighbours were killed in Coalition strikes on 12 October 2017, after the strike CNES/Airbus DS "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Fayad Mohammed and his daughters Wafa’, Fadda and Tamam; Ammar al-Faris; Reem al-Maddad, Yusra Abd-al-Aziz, and baby Razqiya Habib; Jasim Hamal and Salem Hamad. They were among the 16 civilians killed in Coalition air strikes on 12 October 2017 in Raqqa Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Men wait by the side of the road for casual labour in Raqqa. Many end up clearing partially destroyed or damaged buildings, a very risky endeavour as many building were mined by IS and civilians are frequently killed and injured by mines Amnesty "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Satellite images showing the Aswad family’s building before it was destroyed in a Coalition air strike which killed eight civilians, five of them children, on 28 June 2017 CNES/Airbus DS "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Satellite image showing the Aswad family’s building after it was destroyed in a Coalition air strike which killed eight civilians, five of them children, on 28 June 2017 CNES/Airbus DS "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Amal Othman, 13, and her brothers Ammar, 8 and Mahmoud, 17; and Jamal Aswad, 41 – four of the eight victims killed in a Coalition air strike on 28 June 2017 in Raqqa Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Low-income district west of the Jezra intersection on the western outskirts of Raqqa city destroyed by the Coalition shelling started in June 2017 Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Satellite image showing the houses where 16 members of the Fayad family and neighbours were killed in Coalition strikes on 12 October 2017, before the strike CNES/Airbus DS "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Satellite image showing the houses where 16 members of the Fayad family and neighbours were killed in Coalition strikes on 12 October 2017, after the strike CNES/Airbus DS "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Ali Hassan Nafa; Mahdia Hashish and her husband Hussein Ali; Hussein Hashish, Mohammed Hashish and Hussein Ibrahim Hashish, and Mohammed Ali Hashish Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Harat al Badu, a built up area in central Raqqa, next to the stadium. It was the scene of the final battle in the city between SDF/Coalition forces and IS Amnesty International "War of Annihilation" – devastating toll on civilians in Raqqa, Syria Map showing where the Badran, Hashish, Aswad and Fayab families were living before the coalition air strikes Unosat /Amnesty International

Airwars said that a possible reason behind the UK’s refusal to acknowledge civilian harm was due to a reliance on “observable” evidence as proof – such as imagery captured by aircraft that showed civilians near the target area – while dismissing reliable reports from the ground.

In the entire air campaign against Isis in both Syria and Iraq, the UK has conceded responsibility for just one civilian casualty, from a Reaper drone strike in Syria earlier this year – despite more than 1,700 RAF air strikes.

Lloyd Russell-Moyle, a Labour MP and member of the Committee on Arms Export Controls, said: “The government’s assertion that no civilians have been killed in 1,700 British strikes, mostly in densely populated urban areas in Mosul and Raqqa, is part of a wider strategy of denial around the consequences of Britain’s military campaign in Syria and Iraq.”

“Failure to account for the deaths of civilians today imperils civilians tomorrow,” he added.

An MoD spokesperson said: “This has been the most transparent air campaign in history. All RAF missions comply fully with international humanitarian law, are meticulously planned and every care is taken to minimise the effect of our military action on civilians and civilian objects.”

Amnesty’s criticism of the UK’s role was preceded by a scathing assessment of the coalition’s Raqqa campaign as a whole, one year after it declared victory in the city. The rights group said Monday that the coalition’s failure to properly investigate claims of civilian casualties was “a slap in the face for survivors trying to rebuild their lives”.

“It is completely reprehensible that the coalition refuses to acknowledge its role in most of the civilian casualties it caused, and abhorrent that even where it has admitted responsibility, it accepts no obligation towards its victims,” said Kumi Naidoo, Amnesty International’s new secretary general, who recently visited Raqqa.

Raqqa's fall: A journey into the heart of Isis’ failed caliphate

In a report released in June, Amnesty International said its own investigation into the coalition’s campaign in Raqqa had revealed “prima facie evidence that several coalition attacks which killed and injured civilians violated international humanitarian law”.

A spokesperson for the coalition conceded Monday that “the cost of liberating Raqqa came at a very high cost”, but insisted there was no alternative.

“The fighting to liberate the citizens of Raqqa was often house to house against an enemy with no regard for human life that used IEDs and booby traps every step of the way, and Raqqa citizens as human shields,” said US army Colonel Sean Ryan.

“Liberating the citizens of Raqqa was the goal and the other choice would be to let Isis continue to murder, torture, rape and pillage the citizens of Raqqa, and that is simply unacceptable,” he added.

Mazen Hassoun, a resident of Raqqa who fled in 2014 after Isis killed his brother and now lives in Germany, watched the campaign to liberate his city from afar.