The southern city of Concepcion, one of the worst hit areas in Saturday's massive earthquake in Chile, has decided to extend a curfew in a bid to restore order as the authorities intensified relief efforts in the quake-hit region.

According to Chile's agriculture radio reports, the curfew as of Monday would start one hour earlier from 8:00 p.m. (2300 GMT) and last until noon due to increasing chaos after the quake.

Raping and violent activities have increased following the quake, which has disrupted power and water supply in the hardest-hit towns of Concepcion and Talca.

During the last few days, the lack of power, drinking water and food caused panic among residents in Concepcion, triggering looting in supermarkets and food stores.

In a looting incident witnessed by Xinhua reporters, some people broke the doors of a store and grabbed commodities. They then threw out the loot through the windows on the second floor, while others waiting on the ground picked them up and ran away.

On the day the quake struck, drug stores were the first targets for looting, locals told Xinhua. The food stores were the next.

The situation in the city has now deteriorated to the point that stores will be looted even with the presence of the owners.

In the suburbs of Concepcion, some farmers built stone walls in front of gates and guarded their houses with wooden clubs at hands for fear of looting.

To maintain social order, curfews have been imposed on the Maule region and the city of Concepcion since Sunday.

Riot police have been deployed in Concepcion since Monday. They are now patrolling the streets.

The Chilean government has issued a state of emergency for the regions of Maule and Bio Bio, the most affected areas in the earthquake, so as to create conditions for increasing the amount of troops at the quake-affected zones.

Chilean President Michelle Bachelet on Monday announced more troop deployments in the quake-ravaged central and southern regions to help restore order. Troops sent to those regions are expected to total 7,000 by Tuesday.

Meanwhile, the Chilean government has intensified rescue and relief efforts.

The authorities have set up distribution points for drinking water.

A Xinhua correspondent saw people stand in long queues in front of some supermarkets in Concepcion to get some rations of daily necessities for free.

A number of fuel stations have also been established in the city. But it took up to seven hours for residents to get their ration of fuel.

According to earlier reports, the first batch of food supplies is already on the way from Santiago to the quake-hit regions on Monday.

The authorities also announced plans to reopen highways linking the capital with the southern region of the country on Monday.

The airport of Santiago is expected to reopen on Monday. The airport, 10 km from the capital city proper, had been closed after Saturday's quake and all outbound and inbound flights were postponed or canceled.

According to the Public Works Ministry, flights bound for foreign destinations are expected to resume on Friday.

The Santiago airport was damaged in the quake but its runways and the air control tower were still operating. A number of planes from other countries landed at the airport on Sunday, local media reported.

UN officials in New York has said that the UN system is ready to offer rapid assistance to Chile.

UN humanitarian spokeswoman Elisabeth Byrs said in Geneva that the United Nations would rapidly send aid deliveries to Chile in response to the country's appeal for international aid.

The magnitude-8.8 earthquake struck off central Chilean coasts early Saturday, killing at least 723 people and displacing 2 million others.