UN experts have called on Britain and the US to stop giving weapons to Saudi Arabia for its campaign in Yemen amid evidence that Western bombs are being used in potential war crimes.

A report for the UN Human Rights Council said all sides in the war - the Yemeni government and its Saudi-led backers as well as the Iranian-supported Houthis rebels - may have committed war crimes.

The detailed report said both sides had conscripted child soldiers and carried out acts of torture as well as other human rights violations.

The report found that at least 6,475 civilians have been killed since the Saudi intervention began in March 2015 but said the “real figure is likely to be significantly higher”.

Most of the civilian casualties were caused by airstrikes carried out by the Saudi-led military coalition, the panel of experts said.

The experts concluded that some of the coalition strikes “may amount to war crimes”.

“Individuals in the Government and the coalition, including Saudi Arabia and the United Arab Emirates, may have conducted attacks in violation of the principles of distinction, proportionality and precaution that may amount to war crimes.”