Britain, the United States and France may be complicit in war crimes in Yemen, the United Nations has said.

The western nations could be culpable because they arm and provide intelligence and logistics support to the Saudi-led coalition that has starved civilians as a war tactic.

UN investigators recommended all states impose a ban on arms transfers to the warring parties to prevent them from being used to commit serious human rights violations.

“It is clear that the continued supply of weapons to parties to the conflict is perpetuating the conflict and prolonging the suffering of the Yememi people,” Melissa Parke, an expert on the independent UN panel, told a news conference.

“That is why we are urging member states to no longer supply weapons to parties to the conflict,” she said.

Saudi Arabia and the United Arab Emirates, the main parties in the coalition fighting against the Iran-backed Houthi movement that controls Yemen’s capital, are two of the biggest buyers of British, US and French weapons.

The experts compiled a secret list of “individuals who may be responsible for international crimes”, which was sent to UN human rights chief Michelle Bachelet.

Investigators found potential crimes on both sides, and highlighted the role Western countries play as backers of the Arab states and Iran plays supporting the Houthis.

“There are no clean hands in this combat, in this contest,” panellist Charles Garraway said.

Video shows damaged buildings and homes in Yemen village hit by Saudi-led coalition airstrikes

The report accused the Saudi and UAE-led coalition of killing civilians in air strikes and deliberately denying them food in a country facing famine.

The Houthis, it said, have shelled cities, deployed child soldiers and used “siege-like warfare”.

The report said: “The legality of arms transfers by France, the United Kingdom, the United States and other States remains questionable, and is the subject of various domestic court proceedings.”

“This shocking report should act as a wake-up call to the UK government,” Muhsin Siddiquey, Oxfam‘s Yemen country director, said. “It offers all the proof needed of the misery and suffering being inflicted on the people of Yemen by a war partly fuelled by UK arms sales to Saudi Arabia and other coalition members.

“The UK government’s insistence on challenging the recent appeal court ruling, that arms sales to Saudi Arabia were unlawful, is indefensible.

“Instead of putting arms sales first the UK government should be urging all parties involved to commit to a nationwide ceasefire and negotiations that will lead to a lasting peace.”

Andrew Smith, spokesman for the Campaign Against Arms Trade, said: ”This terrible war has created the worst humanitarian crisis in the world. It can only be fought because of the complicity and arms sales of the UK and other arms-exporting governments.

“This support will be on display next week, when the Saudi regime will be in London for the DSEI arms fair, one of the biggest arms fairs in the world. If the UK government wants to promote peace in Yemen then it must end the arms sales and stop its uncritical support for the Saudi dictatorship.”

Yemen: The decades-long struggle ahead to clear the country of landmines

The Houthis drove Yemen’s government out of the capital Sanaa in 2014.

The Saudi-led coalition of Sunni Muslim states intervened the following year to restore the ousted government, a conflict that has since killed tens of thousands of people.

The prospect of famine has created what the United Nations describes as the world’s biggest humanitarian crisis, where 24 million people rely on aid.