The Obama administration should not sell aerial bombs to Saudi Arabia in the absence of serious investigations into alleged laws-of-war violations in Yemen, according to an international rights group.

The United States Department of Defence announced this week that the State Department had approved a sale of $1.29 billion worth of air-to-ground munitions such as laser-guided bombs and “general purpose” bombs with guidance systems.

“The US government is well aware of the Saudi-led coalition’s indiscriminate air attacks that have killed hundreds of civilians in Yemen since March,” said Joe Stork, deputy Middle East and North Africa director.

“Providing the Saudis with more bombs under these circumstances is a recipe for greater civilian deaths, for which the US will be partially responsible.”

The US Congress has played a role in opposing sales of US weapons used in violation of the laws of war and should do so in this case, Human Rights Watch said in a statement.

A Saudi-led coalition of Arab countries has been conducting military operations in Yemen against Houthi and allied forces since late March.

The United Nations reported that the fighting in Yemen has killed more than 2,500 civilians, most of them in air strikes by the Saudi-led coalition.

Human Rights Watch said it has documented numerous airstrikes that unlawfully failed to discriminate between civilians and combatants or in places such as crowded markets in which there was no evident military target, causing hundreds of civilian casualties.

The United Kingdom and France have also made recent military sales to Saudi Arabia, it added in the statement.

The US Defence Department has also announced State Department approval for the sale of $380 million worth of Joint Direct Attack Munitions (JDAMs) to the UAE, which is part of the Saudi-led coalition conducting military operations in Yemen.

“Until Saudi Arabia investigates apparently unlawful strikes by coalition warplanes and takes appropriate action, the US should not be supplying them more bombs,” Stork said.