Mexico on Friday formally charged 14 federal police officers with attempted murder for an August attack on two U.S. agents, identified by sources as CIA agents, that embarrassed the Mexican government with its powerful northern neighbor.
Mexican security sources have placed responsibility for the attack on corrupt police working in cahoots with drug gangs.
The Attorney General's office said it had issued arrest warrants for the 14 federal police officers, charging them with attempted murder and property damage for the attack which peppered a diplomatic vehicle with 152 bullet holes.
The 14 officers come from the southern Mexico City district of Tlalpan and were already in police custody, the statement said.
"The charged police officers tried to kill two employees of the U.S. Embassy in Mexico and a Mexican Marine," the Attorney General's office said.
Mexican officials had earlier said the fact that police officers used AK47s and were not wearing uniforms suggested a gang-orchestrated hit. However the statement made no mention of any suspected link to organized crime.
Drug cartels take advantage of bad pay for Mexican police to infiltrate their ranks.
The attack took place on a road south of Mexico City, and was initially blamed on a case of mistaken identity. It came when increased cooperation between U.S. and Mexican forces seemed to be yielding results in President Felipe Calderon's six-year offensive against the bloody cartels.
Since 2009, government troops have caught or killed more than 20 major drug lords. However that has led to cartel infighting and fragmentation.
Roughly 60,000 people have died in drug-related incidents during Calderon's term, and the violence was a factor that worked against his party's candidate in last year's presidential election.
President-elect Enrique Pena Nieto, who takes office on December 1, stresses his priority is to reduce violence and focus first on tackling crimes like extortion and kidnapping.
But Pena Nieto, who has led the Institutional Revolutionary Party (PRI) back into power after a 12-year hiatus, has rejected negotiating with the gangs, mindful of the PRI's past reputation for cutting deals.
The CIA has declined to comment on the case, while the two agents, who received non-life threatening injuries, were quickly moved out of the country.
(Reporting by Gabriel Stargardter; Editing by Simon Gardner and Vicki Allen)