Eleven adults also died and 79 people were wounded from bomb that was made by Lockheed Martin and sold to Saudi Arabia
The 9 August attack killed 40 boys aged from six to 11 who were being taken on a school trip. Eleven adults also died and local authorities said 79 people were wounded, 56 of them children. CNN reported that the weapon used was a 227kg laser-guided bomb made by Lockheed Martin, one of many thousands sold to Saudi Arabia as part of billions of dollars of weapons exports.
The Gulf monarchy is the biggest single customer for both the US and UK arms industries. The US also supports the coalition with refueling and intelligence.
The investigative journalism site Bellingcat identified bomb fragments, on photographs and videos taken soon after the bombing, as coming from a laser-guided version of a Mk-82 bomb called a GBU-12 Paveway II. Based on marking on a fin segment of the bomb, Bellingcat traced the bomb to a shipment of a thousand of such bombs to Saudi Arabia, approved by the state department in 2015, during the Obama administration.
A spokesperson for Lockheed Martin referred questions about the bombing to the Pentagon. The defense department has said it does not make tactical targeting decision for the Saudi-led coalition but does provide support to improve targeting.
I will tell you that we do help them plan what we call, kind of targeting, the defense secretary, James Mattis, said. We do not do dynamic targeting for them.
The Bellingcat report cautioned that the bomb fragments had not been photographed where they had fallen, but had been gathered together, leaving open the possibility that they had been planted. CNN said it had worked with Yemeni journalists and munitions experts on its own identification of the bomb.
The Obama administration offered Saudi Arabia more than $115bn in weapons in the course of its two four-year terms, more than any previous US administration, according to a report in 2016.
After the bombing of a funeral hall in October 2016, which killed 155 people, Obama halted the sale of guided munition technology to Saudi Arabia, on the grounds that improved precision would not save civilian lives if the Saudi-led coalition were not taking care to avoid hitting non-military targets. The sales were reinstated by the Trump administrations first secretary of state, Rex Tillerson, in March 2017.
Saudi and US officials have insisted efforts are constantly being made to limit civilian casualties in the campaign against Houthi rebels, but United Nations figures show the civilian death toll rising, with April this year becoming the bloodiest month of the war so far.
According the most recent report by the UN High Commission for Human Rights there have been 17,062 civilian casualties since 2015, including 6,592 dead and 10,470 injured.
The majority of these casualties 10,471 were as a result of airstrikes carried out by the Saudi-led coalition, the report said.
The Trump administration has given unstinting support to Saudi Arabia and the United Arab Emirates, echoing their portrayal of the Houthis as Iranian proxies. Congress, however, has become increasingly sceptical about continuing US arms sales to the coalition.
The ranking Democrat on the Senate foreign relations committee, Bob Menendez, has held up a sale of 120,000 guided munitions to Saudi Arabia and the UAE. The administration could ignore his opposition and go ahead with the sale, but it would risk being over-ridden by the Senate.
I think Congress could block this deal because it has just got so outrageous, said William Hartung, the director of the arms and security project at the Centre for International Policy.
The argument of Trump administration and the Saudis is that the US is giving assistance in improving targeting, but more civilians have been killed in the last year than the year before. Whatever value that fiction might have had is now long gone.