Three people were located by rescuers in a collapsed building on Monday in Concepcion, the hardest-hit town in the megaquake that ravaged central and southern Chile on Saturday.

However, dozens of others who were also believed to be trapped inside the 15-storey Borde Rio apartment building are still missing.

Local authorities told reporters that the three people were found alive under a collapsed wall with the help of a special camera device.

However, the rubbles could collapse at any time and workers are racing against the time to pull them out, according to Concepcion fire department.

The building fell on its side into the street during the 8.8-magnitude tremor, one of the most powerful quakes on record.

There were around 200 inside the building at the time and the mayor's office said on Sunday that some 100 people were trapped inside.

The death toll of the quake has reached 711 as of Monday morning, and is expected to rise further when there is a clearer picture of the overall damage.

Chilean officials said two million people were affected and 1.5 million buildings were destroyed or damaged.

(Xinhua News Agency March 2, 2010)