Weapon that hit bus was 500-pound laser-guided MK 82 bomb made by US defence contractor Lockheed Martin, CNN reports
The bomb used by the Saudi-led coalition in an attack on a school bus that killed 40 children in Yemen last week was sold as part of a US State Department-sanctioned arms deal with Saudi Arabia, munitions experts told CNN.
Working with Yemeni journalists and munitions experts, CNN reported late Friday that the weapon that hit the bus on 9 August was a 500-pound (227kg) laser-guided MK 82 bomb made by Lockheed Martin, one of the top US defense contractors.
Of the 51 people who died in the airstrike, 40 were children, the Houthi health ministry said last week, adding that of the 79 people wounded, 56 were children.
The bomb is similar to the one used in an attack on a funeral hall in Yemen in October 2016 in which 155 people were killed and hundreds more wounded, CNN said. The Saudi coalition blamed "incorrect information" for that strike.
After the funeral hall attack, President Barack Obama banned the sale of precision-guided military technology to Saudi Arabia over "human rights concerns," CNN said, adding that the ban was overturned by the Trump administration's then secretary of state Rex Tillerson in March 2017.
The US says it does not make targeting decisions for the coalition, which is fighting a Houthi rebel insurgency in Yemen, according to CNN, but it does support its operations through billions of dollars in arms sales, the refueling of Saudi combat aircraft and some sharing of intelligence.
On the day of the airstrike, the US State Department called for the Saudi-led coalition to investigate it.
"We are certainly concerned about the reports that there was an attack that resulted in the deaths of civilians. We call on the Saudi-led coalition to conduct a thorough and transparent investigation into the incident," State Department spokeswoman Heather Nauert told a news briefing.
UN Secretary-General Antonio Guterres condemned the air strike and called for an "independent and prompt investigation".
On 13 August, thousands of Yemenis protested against Riyadh and Washington as they took part in a mass funeral for the children killed in the strike.
Many of the children were on a field trip after graduating from summer school, according to a CNN report and video showing the students playing before the attack.
The mass funeral was held in the Houthi stronghold of Saada city, with images broadcast by the rebels' Al-Masirah television.
Mourners shouted slogans against Saudi Arabia and its ally and key arms supplier, the US. "America kills Yemeni children," read several banners.