UK could be prosecuted for war crimes over missiles sold to Saudi Arabia that were used to kill civilians in Yemen

Britain is at risk of being prosecuted for war crimes because of growing evidence that missiles sold to Saudi Arabia have been used against civilian targets in Yemen's brutal civil war, Foreign Office lawyers and diplomats have warned.

Advisers to Philip Hammond, the Foreign Secretary, have stepped up legal warnings that the sale of specialist missiles to the Saudis, deployed throughout nine months of almost daily bombing raids in west Yemen against Houthi rebels, may breach international humanitarian law.

Since March this year, bombing raids and a blockade of ports imposed by the Saudi-led coalition of Sunni Gulf states have crippled much of Yemen. Although the political aim is to dislodge Houthi Shia rebels and restore the exiled President, Abed-Rabbo Mansour Hadi, thousands of Yemeni civilians have been killed, with schools, hospitals and non-military infrastructure hit. Fuel and food shortages, according to the United Nations, have brought near famine to many parts of the country.

Amnesty International, Human Rights Watch (HRW) and other NGOs, claim there is no doubt that weapons supplied by the UK and the United States have hit Yemeni civilian targets. One senior Foreign and Commonwealth Office (FCO) legal adviser told The Independent: "The Foreign Secretary has acknowledged that some weapons supplied by the UK have been used by the Saudis in Yemen. Are our reassurances correct - that such sales are within international arms treaty rules? The answer is, sadly, not at all clear."