US officials were warned last year that Saudi forces were abusing migrants in their attempt to enter the country from Yemen. 

Hundreds of Ethiopian migrants, or possibly "thousands", have been killed by Saudi border guards since 2022, who opened fire "like rain" on the civilians trying to cross through Yemen into the Kingdom to escape the atrocities of regional wars, Human Rights Watch said in a report in early August.

While Riyadh said the claims were "unfounded", previous similar incidents that have been documented suggest that inhumane practices against migrants are a frequent occurrence.

Last week, the government of Ethiopia announced its intention to promptly investigate the mass killings of Ethiopian nationals at the Saudi-Yemeni border in coordination with Saudi authorities. This statement was made on platform X, formerly known as Twitter, a day after the HRW report was released, which triggered worldwide outrage.

The United States, a longstanding ally of Riyadh, called for a comprehensive and transparent investigation into the allegations. A Saudi government source rejected the claims in the report, stating they lacked reliable sources, as per AFP.

In the previous year, UN experts reported unsettling claims that Saudi Arabian security forces engaged in cross-border artillery shelling and small-arms fire, leading to the deaths of roughly 430 migrants in southern Saudi Arabia and northern Yemen during the initial four months of 2022.

Repatriation of Ethiopians from Saudi Arabia began in March of that year under an agreement between the two nations. Ethiopia's Foreign Ministry anticipated around 100,000 citizens returning home over an extended period.

The same US officials were given information in December regarding the Saudi abuse of migrants.

Since then, US officials have not condemned the Saudi conduct, although they have called for an investigation. 

In January, Richard Mills, the deputy US representative to the United Nations, stated that the US was "concerned" about the alleged abuses, during a Security Council briefing on Yemen.

At the time, Mills stated, “We urge all parties to allow U.N. investigators to access both sides of the border to thoroughly investigate these allegations,” without revealing that US and European officials knew of the killings made by the Saudi border guards.

According to a statement sent to The New York Times on Saturday, the US learned about particular allegations after the UN High Commissioner for Human Rights released letters it had sent on the issue to Saudi Arabia and Ansar Allah officials in Yemen in late 2022.

The statement details that the US engaged Saudi officials in order to "express our concern," adding that US diplomats continued to raise those concerns with Saudi officials. 

At the same time last year when US diplomats learned of the border violence, US President Biden had criticized the Kingdom for acting against US interests in some issues. First, they cut oil production, then they refused to impose sanctions on Russia after the war in Ukraine began.

More recently, US officials have been pushing for Saudi-Israeli normalization of ties, something that the Kingdom has resisted as well, asking the US for security guarantees.

Many of those attacked on the border with Yemen, meanwhile, end up in hospitals.

Mujahid Al-Anisi, the head of the emergency unit at Al-Jumhori Hospital, a Yemeni facility near the main crossing zone, told The New York Times Wednesday that cases admitted "daily" include dead and seriously wounded women, children, and elders.

Aid workers and UN officials have been trying to track the violence, but international efforts to investigate are few.

Mwatana stated in September that the remains of roughly 30 Yemeni and Ethiopian migrants were discovered on the Saudi side of the border on May 12, 2022, some with gunshot wounds or evidence of torture. Mwatana's study was cited in a paragraph in a State Department human rights report on Saudi Arabia's actions in 2022.

According to the International Organization for Migration's Missing Migrants Project, at least 788 migrants died near the Saudi border in 2022, primarily from artillery or gunfire. According to the group, the true number of those slain was likely significantly higher.

UN experts confronted Saudi Arabia in October regarding the reports and cited allegations of border agents killing migrants, as well as raping women.

Experts elaborated that, if confirmed, the incidents would constitute a "deliberate policy of large-scale, indiscriminate, and excessive use of lethal force" to dissuade migrants, and they asked Saudi Arabia to rein in its troops.

The Kingdom has denied the allegations, something unsurprising, according to Morris Tidball-Binz, the United Nations’ special rapporteur on extrajudicial, summary, or arbitrary executions.

He hoped the increased public attention on the matter would make a difference in improvements "in terms of respect for, if not protection of, these migrants."