MEXICO CITY, June 6 A fast-moving fire killed 31 children in a day care centre in northern Mexico despite desperate attempts of fire-fighters who punched through the walls and fought their way through flames to rescue babies, toddlers and others trapped inside.

At least 25 children and five employees were hospitalised after Friday's fire in ABC day care in the city of Hermosillo, said Jose Larrinaga, a spokesman for investigators in the state of Sonora, which borders Arizona.

Some of the injured suffered severe burns and might be taken to US hospitals, Sonora Gov Eduardo Bours said.“For now, we're concentrating on saving as many kids as possible,” he said.

There were about 100 children in the centre at the time, with ages ranging from six months to five years, said Guadalupe Ayala, coordinator of Red Cross rescue workers.

Reforma newspaper reported that the building was a converted factory with no emergency exits. Ayala said the centre's exits were inadequate but did not have further details.

“Fire-fighters had to knock holes in the walls to get the children,” he said.

Authorities have identified 27 of the 31 children killed, according to a Sonora government statement on Saturday.The fire may have started at a neighbouring tyre and car warehouse on Friday afternoon, state officials said. Fire-fighters took two hours to control the blaze, the cause of which was still unconfirmed.

Most the children died from asphyxiation or smoke inhalation.

Neighbours rushed to help pull out the children as screaming preschool teachers ran through thick clouds of black smoke, Reforma newspaper reported. Sobbing parents flooded hospitals, desperate for news about their children.

Photographs showed the sidewalk outside the day care centre strewn with upturned, slightly blackened baby seats and cribs. Cribs also could be seen through huge holes punched through the walls.

The Mexican government sent a team of 15 burn specialists, three air ambulances, and other medical equipment, President Felipe Calderon said. Mexico's Social Security Institute outsourced services to the privately run day care centre.

Calderon said he ordered an investigation by Mexico's attorney general.

Building safety violations have been blamed for previous disasters in Mexico.

In 2000, a fire killed 21 people at a glitzy Mexico City disco that only had one available exit, lacked smoke detectors and did not have enough fire extinguishers. Many of the dead were found near the club's emergency exit, which was locked with a chain. More than 140 nightclubs were closed for code violations after that fire.

Last year, 12 people died in a botched police raid at another Mexico City nightclub. Officers blocked the overcrowded club's lone working exit, creating a deadly stampede in which nine patrons and three police died in the rush to get out. The emergency exits had been blocked.—AP