Britain sold the Saudis over 1.5 billion dollars worth of arms last summer that saw Riyadh escalate its deadly military campaign against Yemen, say human rights groups.

From July to September 2015, the British government authorized the sales under an export category which covers missiles, rockets and bombs via five separate licenses, The Guardian cited Saferworld and Amnesty International as saying on Tuesday.

The sales were made just one day after British Prime Minister David Cameron claimed he was trying to “encourage a political process in Yemen,” and that the crisis in the country would not be solved through military intervention, said a Saferworld spokesperson.

 “All of these are for air force end use, with the components for air-to-surface rockets for training purposes,” the spokesperson noted.

He added that the Saudi air force “has bombed hospitals, schools, markets, grain warehouses, ports and a displaced persons camp and helped to turn Yemen into a living nightmare.”

Amnesty International UK’s head of policy, Allan Hogarth, said that these licenses were being signed off by British officials as “hundreds - possibly thousands - of Yemeni civilians" were being killed by Saudi Arabia’s "terrifying barrage of indiscriminate" airstrikes.

“The law is crystal clear: any Saudi attack, whether deliberate or not, that fails to adequately protect civilians is a violation of international law. And our obligations are equally clear – as a major supplier of Saudi Arabia’s weaponry, the UK is legally obliged to suspend arms exports,” he noted.

Last month, the Campaign Against Arms Trade NGO reported that the UK had sold over eight billion dollars of military hardware to Riyadh since Cameron took office in May 2010.   

Cameron has been under pressure to halt arms sales to Saudi Arabia which faces massive criticism over its war on Yemen which has claimed the lives of over 7,500 people over the last nine months.