The US-led coalition campaign to liberate the Syrian city of Raqqa from Islamic State killed hundreds of civilians and injured thousands, a charity has claimed.

Ahead of the first anniversary of the start of the offensive, Kate Allen, the director of Amnesty International UK, said Britain “needs to come clean over its role in this carnage”.

War Of Annihilation: Devastating Toll On Civilians, Raqqa, published by Amnesty today, claims coalition air and artillery strikes detailed within it “appear either disproportionate or indiscriminate or both and as such unlawful and potential war crimes”.

“Civilians in Raqqa have suffered grievously at the hands of IS, but they’ve also been imperilled by the coalition’s disproportionate aerial attacks,” Ms Allen said.

“The coalition’s operations in Raqqa have killed hundreds and injured thousands of civilians and the UK needs to come clean over its role in this carnage.

“Having conducted more than 200 airstrikes in Raqqa, the UK needs to be able to show that its targeting was proportionate and that it took proper measures to avoid unnecessary civilian casualties in its joint operations with the US and others.

“Instead of repeating a mantra about there being ‘no evidence’ of civilian casualties from UK airstrikes, the Ministry of Defence (MoD) should publish proper data about its Raqqa attacks – dates, times, locations, weapons used and intended targets. Crucially, ministers should explain how the UK has investigated the impact of its attacks in both Raqqa and Mosul.”

In response, coalition spokesman US Army Colonel Sean Ryan invited Ms Allen to “leave the comforts of the UK” and to head to Syria and Iraq to see how they are “fighting an enemy that does not abide by any laws, norms or human concern”.

“There, she can personally witness the rigorous efforts and intelligence gathering the coalition uses before any strike to effectively destroy IS while minimising harm on civilian populations,” he said.

“She can see firsthand our enemy using civilian non-combatants as shields against (the) coalition in order to sadistically claim that the coalition is ‘killing’ civilians.

“Finally, she can see the painstaking efforts we make to assess allegations of civilian casualties.”

He said Amnesty International has not contacted the coalition for details on how strikes are conducted.

Col Ryan said the findings collated in the report which claim strikes were disproportionate or indiscriminate are “more or less hypothetical”, and stressed that any “non-combatant death or injury is a tragedy”.

Amnesty researchers visited 42 coalition airstrike sites and interviewed 112 survivors and witnesses – who told of the destruction caused by the aerial bombardments.

The charity said the harrowing stories of immense family losses stand in stark contrast to the coalition’s claims that they took great pains to minimise civilian casualties.