in what observers say is a “show of compliance” by Mexican authorities. The handover comes just days before 25 percent tariffs on Mexican imports by US President Donald Trump are due to come into effect.

Trump has long taken aim at what he says is Mexico’s failure to control drug cartels. He has referred to them as “quasi-government organisations” in some parts of the country and blames Mexico, in particular, for the flow of highly addictive fentanyl, a synthetic opioid, into the US in recent years. A statement from the Mexican attorney general’s office said: “This action is part of the efforts of coordination, cooperation and bilateral reciprocity, within the framework of respect for the sovereignty of both nations.”

The US confirmed it had taken the 29 prisoners into custody in a statement by Attorney General Pamela Bondi. There are so far few details about where they are being held.

The US Department of Justice has released a list of federal courts where the 29 defendants are to be charged, but it is unclear when exactly this will happen. They all face charges that include racketeering, drug trafficking, murder, illegal use of firearms and money laundering.