Distraught parents arrive at the nursery after learning of the fire
At least 38 children have been killed in a fire that swept through a state-run day-care centre in north-western Mexico, officials say.
The fire broke out at the ABC centre in the city of Hermosillo in Sonora state.
Dozens of children were taken to hospital suffering from burns and smoke inhalation. Officials warn that the final death toll may rise.
The fire appears to have started in a tyre depot with flammable materials next to the day-care centre.
"We're still investigating what caused the fire," said Jose Larrinaga, a spokesman for the Sonora prosecutor's office.
Local media say the blaze spread so rapidly that some children could not be taken out of the centre.
President Felipe Calderon expressed his "profound pain" over the tragedy in the centre, which was run by Mexico's social services.
Fire fighters had to knock holes in the walls of the building to rescue children.
Officials said the fire was later put out, but that it may take hours for rescuers to sift through the gutted building.
Dozens of ambulances are surrounding the area with thick smoke in the air, the BBC's Steve Gibbs in Mexico says.
Terrified parents rushed to city hospitals - desperate for news about their children, many of whom remained unaccounted for.
At least 176 children are reported to have been at the centre when the fire began.
The children's age reportedly ranged from six months to five years.
Mexican commentators are already asking why the day-care centre was situated next to the depot, our correspondent says.