Washington (AFP) - The Saudi-led coalition fighting in the conflict in Yemen dropped decades-old US-made cluster bombs in a civilian area, independent monitor Human Rights Watch said Thursday, branding it a war crime.
The group's report included a photograph of a section of casing from a CBU-58 cluster bomb, which it said showed it was manufactured in 1978 at a US ammunition plant in Tennessee.
The United States is a close ally of Saudi Arabia and supplies much of the ordnance its forces use, but it has not exported cluster bombs of the type found in Sanaa for many years.
The watchdog's report said the cluster bombs hit a residential neighborhood in Yemen's capital Sanaa and left the tell-tale pockmarks of multiple exploding bomblets on civilian buildings.
It was not immediately clear whether anyone was hurt, but such bombs are indiscriminate weapons.
This is especially true of older models such as the one found in Sanaa because they often contain dud rounds that linger in the area and explode long after the strike.
"The coalition's repeated use of cluster bombs in the middle of a crowded city suggests an intent to harm civilians, which is a war crime," said Steve Goose, arms director at HRW.
The United States said it was aware of the report and would continue to work closely with its allies to urge them to adopt tactics that would prevent the loss of innocent life.
"We continue to urge all sides in the conflict, including the Saudi-led coalition, to take pro-active measures to minimize harm to civilians and to investigate all credible allegations of civilian harm," State Department spokesman John Kirby said.
"We've previously discussed reports of alleged use of cluster munitions with the coalition, underscoring that such weapons should not be used in locations where civilians are known to be present."
Yemeni groups, the United Nations and other observers have been increasingly concerned by the mounting civilian toll in Yemen and the dire humanitarian crisis.
Yemen descended into chaos in March when the coalition began air strikes to push back Huthi rebels who had seized Sanaa.
More than 5,800 people have been killed and 27,000 wounded since then, according to UN figures.