More than 60 people have reportedly been killed in the continuing series of attacks since early September “in circumstances that find no justification in international law,” Volker Türk said in a statement.

He urged the US to halt its “unacceptable” operations and take measures to prevent the “extrajudicial killing of people aboard these boats, whatever the criminal conduct alleged against them.”

Beyond the law

The United States has defended the operations as part of its ongoing efforts to combat drug trafficking and terrorism, asserting that they fall within the framework of international humanitarian law.

Mr. Türk rejected that argument, stressing that countering illicit drug trafficking is a law-enforcement matter, governed by careful limits on lethal force set out in international human rights law.

He emphasised that the intentional use of lethal force is lawful only as a last resort when individuals pose an imminent threat to life.

Call for investigations

“Based on the very sparse information provided publicly by the US authorities, none of the individuals on the targeted boats appeared to pose an imminent threat to the lives of others or otherwise justified the use of lethal armed force against them under international law,” Mr. Türk said.

The High Commissioner called for prompt, independent and transparent investigations into the reported attacks.

While acknowledging the serious challenges posed by drug trafficking, Mr. Türk urged the US to ensure that all counter-narcotics operations respect international law, including the treaties to which it is party.

“The United States should investigate and, if necessary, prosecute and punish individuals accused of serious crimes in accordance with the fundamental rule-of-law principles of due process and fair trial, for which the US has long stood,” he concluded.