The Mexican government says two US agents who died last weekend in a car crash had not been authorised to operate in the country. The officials, who reportedly worked for the CIA, had taken part in a raid on suspected drug labs in the northern state of Chihuahua before their vehicle skidded off a mountain road and exploded. Following an investigation ordered by President Claudia Sheinbaum, Mexico's security ministry stated that 'neither had formal accreditation to participate in operational activities' and that federal authorities had not been informed of their presence. The incident comes amid at-times fraught relations between Mexico and the US on various issues including counter-narcotics. Sheinbaum faces pressure from US President Donald Trump to intensify efforts against drug trafficking, but has declined offers for US-led operations within her country. She has insisted that foreign officials must receive prior clearance from the federal government to operate in Mexico. Immigration records indicated one agent entered Mexico as a visitor, while the other traveled on a diplomatic passport, and both lacked the necessary accreditation for operational activities. The crash occurred on April 19 during a convoy's return from targeting methamphetamine labs, also resulting in the deaths of two members of Chihuahua's State Investigation Agency. State Attorney General César Jáuregui described the US officials as 'instructor officers' engaged in training activities supported by a general exchange with US authorities. Despite ongoing intelligence sharing, Sheinbaum emphasized that there are 'no joint operations on land or in the air.' A recent investigation revealed that the CIA has been conducting covert operations in Mexico to track down notorious drug traffickers, with some units receiving training and support from the agency. Sheinbaum's government is currently under pressure to escalate its response to drug trafficking as part of the broader security collaboration with the US, without compromising Mexican sovereignty.