Yemen's horror exposes the deadly hypocrisy of arms exporters including Britain and the US

The airstrike on Abs Rural Hospital in Yemen's Hajjah governorate on 15 August was the fourth attack on a Médecins Sans Frontières (MSF) hospital in 10 months. That didn't lessen the shock.

Sixteen-year-old ambulance driver Ayman Issa Bakri was among the 10 dead. He had been working there since MSF began supporting the hospital in the summer of 2015. When his body was found near the impact site, he was still holding the woman he had been transferring from the ambulance to the A&E.

Shortly after, MSF announced it was winding up its operations in Yemen; it is hard to imagine the despair that Yemenis feel when the only hospital for miles disappears.

At the site of the ruined hospital, Amnesty International identified remnants of bombs that appear to have been manufactured either in the USA or the UK. This would be consistent with what we know about prolific arms exports by these countries to Saudi Arabia and other members of its military coalition.

Meanwhile, UK and US delegates were preparing to attend the second Conference of States Parties to the Arms Trade Treaty (ATT), which wraps up in Geneva today. The ATT sets out prohibitions on transfers of weapons where it is known that they would be used in war crimes – for example in indiscriminate or direct attacks against civilians. The UK has ratified the treaty, so it is bound by its rules; as a signatory, the USA must not take any action to undermine its object and purpose.

In light of extensive knowledge about how the Saudi Arabia-led coalition is using certain weapons to carry out indiscriminate and direct attacks on hospitals and other civilian targets, they should not be authorising any transfers of arms to the coalition for use in the Yemen conflict. This is precisely why we have repeatedly called for a comprehensive embargo on arms transfers that could be used by any of the warring parties in Yemen.

Children make up a third of the 3,799 civilians killed in Yemen since the coalition campaign began in March 2015.

In a statement to the conference on 23 August, the UK delegation urged other States Parties to 'redress practices that fall short of the treaty's ideals' and to be willing to accept criticism of their conduct. The hypocrisy of this call is astounding, coming after nearly three weeks of renewed horror for Yemeni civilians, again the victims of indiscriminate attacks by a Saudi Arabia-led coalition which is replete with UK-made weapons, including munitions and military aircraft.

Since peace talks in Kuwait collapsed on 6 August, airstrikes against the Houthi armed group have resumed, with dire consequences for civilians. Just two days before the attack on Abs Hospital, 10 children were reportedly killed and 28 injured when their school was bombed in Sa'da. There is nowhere that children can feel safe; they make up a third of the 3,799 civilians killed in Yemen since the coalition campaign began in March 2015.

Amnesty International has documented time and again how ATT States Parties continue to supply the Saudi Arabia-led coalition with weapons of the type used for attacks against civilians and civilian infrastructure in Yemen. By doing so, they risk complicity in such unlawful attacks.

The Saudi Arabia-led coalition has also used cluster munitions, banned by an international treaty to which the UK is a signatory. On our most recent mission to Yemen we found remnants of UK and US-made cluster munitions scattered around people's houses and hanging from trees, as well as evidence of their consequences: children missing fingers, parents missing children.

In Geneva this week, the Control Arms Coalition and Pax reminded delegates of the humanitarian suffering of civilians in Yemen. The silence of the USA and the UK at this meeting was deafening. Meanwhile France did not even bother to attend. Along with the UK, US, Germany and Spain, France is among Saudi Arabia's top five arms suppliers – according to its own annual report it authorised the export of up to US$18 billion worth of arms to the country in 2015.

Silence on civilian casualties in Yemen is undermining one of the international community's most important tools for protecting civilians caught up in wars.

The refusal of Saudi Arabia's main arms suppliers to engage in any kind of public debate about what is happening in Yemen is shameful. Blunt denials, vague platitudes, or just plain silence are becoming the standard responses to reams of credible information on how the Saudi Arabia-led coalition are using those arms to commit serious violations of international human rights and humanitarian law. Photos of munitions of the type being sold by the UK to Saudi Arabia in the vicinity of bleeding toddlers and houses flattened into tombs are not considered important enough to prompt even a brief public statement from the UK.

States parties, including the UK, continue to encourage others to join the ATT. But if they are unwilling to scrutinise their own conduct or penalise violations, they will undermine the treaty's founding spirit and risk turning it into little more than a public relations exercise.

There must be zero tolerance for states who flout the ATT's obligations. Amnesty International is calling for a requirement for arms exporters not to approve an arms transfer until importing states provide legally binding guarantees ensuring the intended end users of those arms will respect human rights and the rule of law. For example, the UK could not currently authorise any arms transfer to Saudi Arabia until it had a legally binding guarantee that those arms would not be used in Yemen.

Silence on civilian casualties in Yemen is undermining one of the international community's most important tools for protecting civilians caught up in wars. A high-level ambassador told Amnesty International at the Conference that since the ATT is only two-years-old we need to "exercise patience", and give it time. However, states like the UK, France and the USA have ample resources to control their arms exports to ensure they do not fuel atrocities – they can and should lead the way.

In the meantime, unless ATT States Parties begin to live up to the treaty's obligations, all Yemenis in hospital beds can do is pray that the next round of airstrikes hits somewhere else.

Rasha Mohamed is a Yemen Researcher at Amnesty International and Rasha Abdul Rahim is an Arms Control Campaigner at Amnesty International