The medical facility – Abs Rural Hospital, run by Doctors Without Borders (MSF/Medecins Sans Frontieres) – was hit by a strike that left 11 people dead and 19 others injured. Over 4,500 patients had been treated in the hospital since MSF began supporting it.

The attack was the fourth over the last 10 months on an MSF facility in Yemen, and led the organization to close its hospitals in the north of the country.

Experts analyzed photos of munitions used in the bombing and concluded that a US-made precision-guided Paveway-series aerial bomb was among them.

“Any attack on a medical facility in a war zone is an affront to humanity, yet this bombing is sadly just the latest in a grim series of attacks on hospitals and clinics by the Saudi Arabia-led coalition,”Philip Luther, Research and Advocacy Director for the Middle East and North Africa at Amnesty International, said in the official press release.

“Deliberate attacks on hospitals and medical facilities are serious violations of the laws of war and can never be justified. Hospitals, which have special protection under international humanitarian law, should be safe places of treatment and recovery,” he added.

“It is outrageous that states have continued to supply the Saudi Arabia-led coalition with weapons, including guided and general purpose aerial bombs and combat aircraft, despite stark evidence that those arms are being used to attack hospitals and other civilian objects and in other serious violations of international humanitarian law.”

Luther called for a “comprehensive embargo on all weapons that could be used by any of the warring parties in Yemen,” and punishment for those behind the attack.

The latest Amnesty report follows another release by the group which says that Saudi Arabia is using US-delivered white phosphorus for its attacks in Yemen.

Under US law, the substance can only be used to signal to other troops and for smokescreens. However, human rights activists are concerned that white phosphorus is being used to attack civilians. It can cause serious injury if it comes in direct contact with the skin, burning it to the bone.

Two days ago, separate research, conducted by the Guardian, found that one third of 8,600 Saudi-led strikes in Yemen since March 2015 have targeted civilian sites such as hospitals, schools, and mosques.

It comes as the US Senate is set to vote on a draft bill that could stop a $1.15 billion weapons and military equipment delivery by the US to Saudi Arabia.

The bill was approved in August, but later that month 64 Senators signed a letter to halt the sale – ensuring that the Senate would discuss it.

Last November, the US State Department okayed the delivery of weapons worth $1.29 billion to Saudi Arabia, despite the fact that Amnesty International had repeatedly revealed they were being used in illegal and deadly attacks on civilians.

Since coming to office seven years ago, the Obama administration has made over $115 billion worth of arms sales to the Saudis – more than any other US presidential administration, a report in the Security Assistance Monitor said.

Over 3,700 civilians have been killed and some 2.8 million displaced by the ongoing war in Yemen, now in its second year, according to the latest estimates by the UN Office of the High Commissioner for Human Rights.

After analyzing public source data for some 8,600 air raids conducted by the Saudi-led coalition between March 2015 and August this year, the Yemen Data Project concluded that only 3,577 sites were of a military nature. Some 3,158 were listed as non-military, while 1,882 strikes were classified as unknown, the Guardian said in its analysis of the data.

Furthermore, the data which has been collected from open sources and cross-referenced by the NGO using a wide range of information showed that Saudis flew 942 air raids on residential areas. The planes managed to strike 114 markets, 34 mosques, and 147 school buildings, in addition to 26 universities. The information also revealed that Riyadh targeted transportation network, striking some 37 transport sites.

The Yemen Data Project said that the coalition hit more non-military sites than military in five of the last 18 months, with some target areas being struck on multiple occasions. One particular school was hit nine times, a deplorable fate that is shared by one market that was hit at least 24 times.

Saudi Arabia which has been repeatedly called to world attention over its indiscriminate bombings of civilian targets dismissed the report, with Saudi Foreign Minister Adel al-Jubeir telling the Guardian that the figures are “vastly exaggerated.” 

He blamed the Houthi fighters of turning civilian buildings such as schools and hospitals into “command and control centers” and“weapons depots” that no longer made the sites civilian targets.

“They are military targets. They might have been a school a year ago. But they were not a school when they were bombed,” he said.

The Guardian revealed the findings at a time when UK’s International Development and Business committees urged London to suspend arms sales to Saudi Arabia. The Kingdom is the second largest purchaser of British weapons importing some $3.7 billion worth of arms since the bombing of Yemen began. Opposition parties have blamed the ruling elite for not dealing with the matter and not stopping arms transfer to the Kingdom

“It’s sickening to think of British-built weapons being used against civilians and the government has an absolute responsibility to do everything in its power to stop that from happening,” the UK’s shadow defense secretary, Clive Lewis, told the Guardian.

Lawmakers in the US are also calling to ban arms sales to Riyadh after Saudi-led bombing campaign continues to receive worldwide condemnation for its conduct from human rights groups and the UN.

“Selling $1.15 billion (£870 million) in tanks, guns, ammunition, and more to a country with a poor human rights record embroiled in a bitter war is a recipe for disaster and an escalation of an ongoing arms race in the region,” Republicans Rand Paul said earlier this week.

Last month 64 members of the House of Representatives signed a letter urging President Barack Obama to delay the sale after the State Department approved the potential delivery of more than 130 Abrams battle tanks, 20 armored recovery vehicles and other equipment to Saudis.

Washington justified the sale as the means to secure long-lasting peace in the region, without altering the “basic military balance in the region.”

“This proposed sale will contribute to the foreign policy and national security of the United States by helping to improve the security of a strategic regional partner which has been and continues to be a leading contributor to political stability and economic progress in the Middle East,” Security Cooperation Agency said in the press release.

Saudi Arabia sent troops to Yemen to restore ousted Sunni president Abd-Rabbu Mansour Hadi to power in March 2015. The intervention claimed the lives of at least 10,000 people, including almost 4,000 civilians, according to conservative UN estimates. The majority of victims were killed in airstrikes. Peace talks mediated by the UN which aimed to bring hostilities to an end faltered last month and fighting continued.