Britain has been backing an ongoing Saudi-led military campaign in Yemen through massive arms sales and military support
The new Prime Minister of the rebel Houthi government in Yemen has accused Britain of war crimes in his first interview since taking power.
The government organisation has just been set up after over 20 months of fighting between the Iranian-backed Houthi rebels and the Yemeni government - supported by a Saudi-led coalition of Gulf States.
Oxfam has said the country is being "slowly starved to death" by the ongoing conflict.
Prime Minister Abdulaziz bin Habtour spoke scathingly about how the British Government cares more about making profits from arms sales to Saudi Arabia than the humanitarian disaster in his country.
"They have sold cluster bombs to Saudi Arabia," he told Sky News in his office in the capital Sana'a. "They know the Saudis are going to drop them on Yemen ... in Sa'adah and in Sana'a and other provinces.
"I don't think they are guilty of war crimes, I believe so. They are participating in the bombing of Yemen people."
A nose cone used to protect a British-made Storm Shadow cruise missile, which the Ministry of Defence calls "arguably the most advanced weapon of its kind in the world" was reportedly found among American cluster bombs in Sa’adah City.
It was clearly marked with a UK identifying stamp.
Britain is a long-time ally of Saudi Arabia and has been backing the Middle Eastern power’s ongoing military campaigns through massive arms sales and military support.
The United States has supported the coalition against the Houthis over the past year with intelligence, weapons and mid-air refuelling aircraft.
A soldier who had collected a pile of cluster bomb shells said the nose cone landed four days earlier.
Pictures of bomb parts found in fields in the city have been examined by independent bomb experts who told Sky News they were "two BL-755 submunitions from an air-dropped BL-755 cluster bomb, most certainly UK made."
The pictures have been widely shared locally.
Britain agreed to stop using and selling cluster bombs around six years ago.
The words of the Convention on Cluster Munitions also state that signatories will "never under any circumstances assist, encourage or induce" anyone to use such munitions.
However, Saudi Arabia and the United Arab Emirates are believed to have British-made cluster bombs bought in the 1980s and 1990s.
Swathes of Sa'adah City have been reduced to rubble. In the Old City, which dates back to the 9th Century, barely any building has been left untouched by the airstrikes which have pounded it, including the mosque built more than 1,200 years ago.
"We used to think Britain was our friend," one old man told Sky News. "Now we think they are criminals because of what's happening here. They're committing crimes, killing our children and pregnant women."
Sa'adah City is a stronghold of the Houthis, sitting in the north of Yemen near the Saudi border.
The coalition campaign is backed by the US, Britain and France, while the Saudis say the Houthis are aided by Iran.
There have been claims of human rights abuses on both sides but it is the ferocious air campaign by Saudi Arabia that has drawn worldwide concern after hospitals, schools, funerals and weddings were hit.
A UK Government spokesperson said: "We are aware of reports of an alleged airstrike on a school using UK-supplied weapons and are seeking further information regarding the incident.
"The UK Government takes all allegations of international humanitarian law violations very seriously. We will analyse this allegation in the usual way.
"This analysis will be used to contribute to our overall view on the approach and attitude of the coalition to international humanitarian law, as part of all the information available to us."