At least 12 people were killed and more than 60 injured in an explosion at an apartment building in central Argentina late Tuesday. At least 16 people were reported still missing after the blast that was attributed to a gas leak in the heating system, said Raul Rainone, civil defence official in the city of Rosario, about 300 kilometres from Buenos Aires. Sante Fe provincial governor Antonio Bonfatti characterized the situation as "dramatic." "The destruction is massive, I can't find the words to describe it," he said. "The fire was enormous, someone must be held responsible." The blast and fire also damaged other buildings and businesses. "It was a disaster, people running, the building totally engulfed in flames, windows shattering all over, debris covering the block," dpa quoted the manager of a nearby building as saying. Firemen fought the blaze and rescued trapped residents with harnesses and long ladders. Municipal health secretary Leonardo Caruana said three of the injured victims were in critical condition.