Amnesty International and other human rights groups have denounced Western arms sales to Saudi Arabia and its allies in a war which the United Nations says has killed more than 10,000 people and left 8.4 million on the brink of famine.

Spanish broadcaster Cadena Ser reported the Defence Ministry had started a process to cancel a contract signed between Spain's former government and the Gulf Arab state in 2015 to sell 400 laser-guided bombs.

The broadcaster said the bombs would have been used in Yemen, where U.N. human rights experts have said air strikes by the Saudi-led coalition have caused heavy civilian casualties and some may amount to war crimes.

"We confirm the news," a Defence Ministry spokeswoman said, declining to give any further details. There was no immediate response from Saudi authorities.

Cadena Ser said the Socialist administration of Prime Minister Pedro Sanchez, who took over in Madrid in June after toppling his conservative predecessor, would pay back 9.2 million euros already paid for the material.

The ministry said last month it had never sold arms that could be used against a civilian population, condemned the killing of non-combatants in Yemen, and said it would review any possible sales that had not yet been closed and could be involved in attacks on civilians.

In April, Spain signed a framework agreement to sell warships to Saudi Arabia in a deal estimated to be worth around 1.8 billion euros.

The United States and Britain are amongst the main foreign arms suppliers to the Saudi-led coalition fighting to reinstate the internationally-recognized government that was ousted from the capital Sanaa by Iranian-aligned Houthi rebels in 2015.

REUTERS