Firefighters have located survivors in a destroyed building in Concepcion. And desperate residents help themselves to what food they can find in damaged supermarkets. Other survivors are sifting through rubble to see what can be salvaged from their devastated homes.

A rescue worker searches for survivors after a major earthquake in Constitucion March 1, 2010.

Rescue workers hurried to save at least three survivors from the rubble of a building in the quake-ravaged city of Concepcion. They reported that sounds were coming from inside the building.

A rescue worker said, "In the 602nd department, we've made some kind of contact. We made the confirmation with the sound of shattering of glass. From the information we have, there are 3 people. We plan to make small holes to make verbal contact or to insert some type of microcamera."

Meanwhile, shortages of drinking water and food have worsened the effects of the disaster.

Some people, desperate for food, took sacks of flour from a warehouse in Concepcion. They said they had no choice but to help themselves.

A local resident said, "We have more than 1,500 people. We do not have medicine, there pregnant women who are about to give birth, there are children. Imagine the desperation. They are saying that we are going around robbing, who are we robbing when we have a truck of flour for 1,500 people."

Some of the survivors sifted through rubble on Monday to look for what may be left from their devastated homes.

A local resident said, "I found my mum's shoes and I want to give them back to her if I find her."

The magnitude 8.8 earthquake on Saturday killed more than 700 people, and the death toll is expected to rise.