Saudi coalition jet fighters carried out a series of airstrikes on a Houthi rebel-run prison in southwestern Yemen early Sunday morning, killing more than 100 and wounding another 40. The attack ranks among the worst in a long string of war crimes committed by Saudi Arabia, with the full backing of the American and British governments, in its four-year-long effort to reimpose a puppet government on the poorest country on the Arabian Peninsula.

Residents reported that seven separate airstrikes slammed into a former university building in the southwestern city of Dhamar which had been converted into a detention center by the Houthis, obliterating the structure and killing or wounding every single detainee. Members of the International Committee of the Red Cross (ICRC) rushed to the scene of complete devastation to search for possible survivors and comb through the rubble for the bodies of victims.

While the Saudi-led coalition justified the horrific attack by claiming the site had been used by the Houthis to store drones and missiles, the ICRC confirmed that the attack had in fact destroyed a prison where its representatives had previously visited detainees.

“It’s a college building that has been empty and has been used as a detention facility for a while. What is most disturbing is that [the attack was] on a prison. To hit such a building is shocking and saddening—prisoners are protected by international law,” Franz Rauchenstein, the head of the ICRC’s delegation in Yemen told the Guardian.

The Saudi monarchy, given the green light by Obama in March 2015 and now with the unyielding support of Trump, has been waging a bloody assault on Yemen in an effort to return its puppet President Abd Rabbu Mansour Hadi back to power after he was forced to flee the country in the face of an advance by the Houthis. The US claims the Houthi rebels are backed by Iran and that the war is a critical component of its efforts to counter Tehran’s influence in the region. Despite repeated assertions, the Trump administration has yet to provide any evidence to back up its allegations.

Trump reaffirmed Washington’s support for the Saudi-led slaughter in Yemen in April when he vetoed a congressional resolution which would have required the Pentagon to end direct military support. Without enough votes to overcome the president’s veto, the bill was seen as an opportunity by a number of current Democratic presidential candidates to make a phony show of sympathy for the broad antiwar sentiments in the US population.

Saudi jets, armed with US and UK bombs and provided with targeting information by US military intelligence officers stationed in Saudi Arabia, have continued to carry out repeated attacks on civilian targets, including schools, hospitals, residential neighborhoods, mosques, funerals and markets. The US had provided coalition jets with mid-air refueling until the end of last year, ensuring maximum carnage.

An analysis of casualty and death toll data published earlier this year by the Armed Conflict Location & Event Data Project (ACLED) found that the total number of people killed in direct political violence in Yemen is approaching 100,000, including 12,000 civilians, between January 2015 and June of this year. ACLED found the Saudi coalition responsible for 68 percent of all civilian casualties recorded.

These figures do not include those civilians, including children, who have died of cholera and malnourishment as a result of a naval blockade enforced by the Saudi-led coalition and the US Navy and airstrikes on critical infrastructure, including water, sanitation and electrical systems. Some 8 million Yemenis are currently living on the brink of starvation.

The global charity Save the Children estimated at the end of last year that as many as 85,000 children under the age of five had died from starvation since the Saudi assault began. And the worst cholera outbreak on record has infected more than 1.2 million people, claiming the lives of more than 2,500.

The Saudi-led coalition has hindered efforts to treat the wounded and sick by repeatedly bombing hospitals, including an attack on a Doctors Without Borders cholera treatment facility in northwestern Yemen in June 2018.

Despite spending billions of dollars, dropping tens of thousands of bombs and thereby creating the worst humanitarian crisis in the world, Saudi Arabia and the US appear no closer to the goal of dominating Yemen today than they did in March 2015 when the onslaught began.

An apparent split has emerged between Saudi Arabia and its main coalition partner, the United Arab Emirates (UAE), in recent months, with Abu Dhabi announcing the pullout of its ground forces from Yemen in July and subsequently turning equipment and positions over to the tens of thousands of militia members whom it has funded and trained.

As a result, a new front has opened up in the war, with Yemeni army forces loyal to Hadi supported by Saudi Arabia fighting the separatist Southern Transitional Council (STC) and allied Security Belt Forces militia backed by the UAE for control over the southern port city of Aden.

On Thursday, airstrikes by UAE fighter jets killed 45 soldiers and wounded dozens of others in an assault which targeted forces loyal to Hadi in Aden and neighboring Abyan province. Dozens of Hadi loyalists have been arrested by the southern separatists on charges of “terrorism.”

With the backing of the UAE, the STC is seeking the re-establishment of the independent state of South Yemen, known officially as the People’s Democratic Republic of Yemen, which existed from 1967 to 1990 with the backing of the Soviet Union. The dissolution of the USSR led to the creation of unified Yemen followed by a failed southern secessionist movement in 1994 which was suppressed by the north.

Meanwhile the Trump administration has continued to carry out the drone war in Yemen which was initiated by Obama under the guise of the so-called “War on Terror.” So far this year there have been nine drone strikes, with at least 10 people killed. While there have been no reported use of US drone strikes in support of the Saudi-led war, an armed US military MQ-9 Reaper drone was shot down over Dhamar by Houthi forces in late August.