City of Rosario rocked by deadly blast that sparked evacuation of downtown area and major rescue effort.

Link to video: Aftermath of fatal Argentinian building explosion

A natural gas explosion has ripped apart an apartment building in the Argentinian city of Rosario, killing at least eight people, injuring 60 and causing officials to evacuate much of the downtown. Officials said 19 people were unaccounted for.

Dozens of people were trapped for a time in the upper floors of the burning building as a plume of smoke billowed up over the country's third-largest city. The building's front and back facades were ripped open but the blast on Tuesday, exposing the shattered remains of apartments inside.

Firefighters working from above and below pulled people out of windows and off balconies as the bottom floors burned. The explosion damaged other buildings for blocks around, and fearing a collapse, police closed buildings and schools in a five-block radius.

The city mayor, Monica Fein, confirmed the death toll and said rescuers were still looking for people in the rubble. She said 19 people were on a list of missing.

Rosario civil defence chief Raul Rainone said the explosion appeared to have been caused by a gas leak in the 10-storey building. Afterwards, the Litoral Gas company cut off gas flow to much of downtown.

The fire took three hours to extinguish and left the building in serious danger of collapse, firefighters said.

Buildings were damaged for several blocks surrounding the blast, with bricks, glass and cement crashing on to the street. Eleven schools were evacuated and several shops and other apartment buildings were damaged.

The national security secretary, Sergio Berni, offered the services of the border police and coast guard to help local authorities.