MEXICO CITY - MEXICO suspended three Social Security Institute officials on Friday pending investigations into whether negligence played a role in a fire that killed 45 children at a day care centre.

The 45th victim died at a hospital Friday, a week after the blaze erupted in the northern Sonora state capital of Hermosillo, state Health Secretary Raymundo Lopez said.

Twenty-one children and three adults remain hospitalized, including five children who have been sent to Shriners Hospitals for Children-Northern California in Sacramento. Lopez said two more children would be sent to US hospitals over the weekend, one to Sacramento and another to Cincinnati, Ohio.

The Social Security Institute, which outsourced services to the privately run day care, said it suspended three officials: Noemi Lopez, the Sonora state day care centre coordinator; Delia Botello, the Hermosillo city day care coordinator, and Emigdio Martinez, the Sonora chief of economic and social benefits.

The institute's top delegate in Sonora, Arturo Leyva, was asked to step down earlier this week. Two state government officials whose wives own the day care have also resigned.

Officials say the fire started at an adjacent warehouse and may have been caused by a short circuit or overheating in the building's air conditioning system. The blaze spread to the day care centre roof, sending fire raining on the children and teachers.

Investigators say there were no fire alarms or extinguishers at the warehouse for cars, tires and paperwork. The day care centre passed a safety inspection on May 26, and its owners have said there were three clearly marked emergency exits.

But firefighters, parents and civilian rescuers said they fought to evacuate the children through the only door that was not blocked and through large holes that neighbours had punched through the walls.

The day care centre fire alarms failed to go off. Sonora Governor Eduardo Bours said that was because they were attached the ceiling panels, and the smoke seeped in through a space between the roof and the panels. -- AP