Mexico City hospital blast: Nine babies DNA tested in bid to reunite children with parents

Several babies survived because their mothers shielded them from the blast

Mexican President Enrique Pena Nieto (3-L) visiting one of the injured from the explosion of a tan truck at Materno Infantil children's hospital (EPA)

Nine babies who were discovered alive after a gas blast at a maternity and children's hospital in Mexico City are being DNA tested by authorities attempting to reunite them with their parents.

A nurse and two infants died and more than 70 people were injured when a gas truck exploded on Thursday near the Materno Infantil children's hospital, where over 100 people were inside at the time.

The huge explosion shot a fireball in the sky and caused over 70 per cent of the hospital to collapse.

Rescuers discovered several babies alive in the rubble on Thursday.

"We have nine DNA tests pending," Mexico City Mayor Miguel Angel Mancera said. "There are parents who have identified their children, but as the babies did not have bracelets on, we have to follow a protocol to identify them."

Rescuers work amid the wreckage caused by an explosion in a hospital in Cuajimalpa, Mexico City (AFP/Getty)

Mancera said some of the infants survived because their mothers shielded them from the blast with their own bodies during the blast.

A leak in a hose from a gas truck, which was fuelling the hospital's tanks, was believed to have triggered the explosion, officials said. Three men operating the gas truck have been detained by authorities.

Additional reporting by agencies