Thirty hours after the 8.8-magnitude megaquake hit Concepcion, the second largest Chilean city, local people embraced the law of jungle to search for food and satisfy other basic needs.

They spent the past 30 hours without light, water and food.

The downtown of Concepcion, a city of 670,000 people located 115 km from the epicenter of the quake, was completely destroyed in the earthquake.

Some citizens gathered on squares, and others set up temporary tents beside rubble. Most citizens seemed depressed as all public services fell into stagnation and no timely assistance was in sight.

On Sunday, they smashed open some of the biggest supermarkets in the city.

The police tried to stop the plunder with tear gas, but failed to control the situation.

"We are ready to pay, but they refused to sell anything to us," some people told reporters.

"This is out of desperation, because we have neither foods nor water," a woman in her 30s shouted from a looted supermarket.

Carrying two boxes of milk, a woman told a local TV channel that she was looking for food for her children. "We do not have anything, it is the need," she said.

Concepcion mayor Jacqueline Van Rysselberghe appealed to the government to send security forces "to restore the order." He said the situation was getting "out of control" due to shortages of basic supplies.

"We need marines and militaries in the streets, because there is chaos. It is terrible. They are razing the supermarkets, fighting like animals for food," Rysselberghe told local radio station Radio Cooperativa.

The mayor said his city is anxiously waiting for aid from the outside world.

"If citizens' basic needs could not be met ... we would face severe security challenges," Rysselberghe said.

Curfew was imposed in Concepcion on Sunday, and troops have been dispatched to areas around Concepcion to preserve order.

Chilean President Michelle Bachelet promised distribution of foods and other material for citizens. Officials from the state emergency center said the operation of assistance has started and some relief material have been sent to tsunami-hit regions.

Due to continuous strong aftershocks and the absence of rescue efforts, some regions in southern Chile have plunged into turmoil. More than 200 prisoners escaped from a prison 350 km south of the capital.

In other most affected regions -- Maule, Bio Bio and Araucania, basic services have also been paralyzed since the earthquake, throwing people into deep anguish. They call on the government to restore the services as soon as possible.

To maintain social order, President Bachelet declared on Sunday a 30-day state of emergency in Maule and Bio Bio.

The president said the death toll has reached 708 and is likely to increase as rescue goes on.

At a news conference, the president said the country was facing "a catastrophe of such unthinkable magnitude" and would need enormous efforts to recover.

Bachelet said the largest death toll of 541 people was in the region Maule, 64 in Bio Bio, and the other 103 deaths were registered in other affected areas.