An angry crowd in Mexico City has burnt alive two police officers and seriously injured another after mistaking them for child kidnappers.
Mexicans fed-up with rising crime have resorted to vigilantism
The agents were taking photos of pupils at a primary school on Tuesday, where two children had recently gone missing.
Live cameras caught the mob beating the officers before dousing two of them with gasoline and setting them ablaze.
It was the latest example of mob justice by Mexicans frustrated by state corruption and soaring crime.
The attack began when residents caught the federal agents in plain-clothes photographing pupils leaving the school in the San Juan Ixtlayopan neighbourhood.
Some in the crowd thought they were kidnappers, while others were simply angry that the alleged kidnappings had not been properly investigated.
The crowd cheered, chanted and shouted obscenities as they attacked the officers before setting them alight.
They were held by the mob for several hours before they were killed.
At one point, the victims, blood streaming down their faces, spoke into the cameras, saying they were anti-terrorism agents.
Police said traffic jams prevented them sending reinforcements to rescue the officers.
Dozens of police in riot gear eventually arrived and dispersed the crowd.
The third officer was rescued and was recovering in hospital.
Federal police director Jose Luis Figueroa said the three agents had been investigating drug dealing in the area.
Mexico has the second-highest number of kidnappings in the world, with some 3,000 reported cases last year.
Earlier this month, a mob threatened to kill a man for allegedly trying to steal a guitar and a tape deck from a community centre, on the outskirts of the capital.