Three strong aftershocks jolted Chile Wednesday four days after the 8.8-magnitude earthquake, sparking panic in the south American country.

An aftershock measuring 6.1 on the Richter scale struck late Wednesday following two aftershocks measuring 6.0 and 5.9 respectively earlier in the day.

In the southern-central town of Concepcion, one of the hardest-hit cities in Saturday's quake, sirens were heard and hundreds of people rushed out their shelters to higher ground.

Chilean authorities issued a tsunami warning after the two earlier aftershocks, but later lifted the alert. However, most of the people in the affected areas said they would still choose to stay outside during the following days, out of fear of more aftershocks.

Saturday's 8.8-magnitude earthquake has killed 802 people, Chilean Vice Interior Minister Patricio Rosende said Wednesday, adding the death toll could rise as rescue work is ongoing.

According to the National Office of Emergency, the number of affected people was probably 2 million.

As Chile saw a flurry of aftershocks, President Michelle Bachelet called on the people to remain calm and urged them "to work together on the recovery of Chile."

She said Chile is ready to recover from the disaster. "We are in conditions to stand up again. This is a moment when we cannot be defeated by the adversity," she said.

The president said the reconstruction of the country "is everybody's work" and at this moment her government's main task is to restore basic services as soon as possible in the most affected zones.

Bachelet also reaffirmed her objection to looting in the last days in the quake-hit areas.

The Chilean government on Tuesday extended an 8:00 p.m.-to-noon curfew to begin at 6:00 p.m. to crack down on looting in Concepcion.

Authorities also added three towns -- Talca, Cauquenes and Constitucion -- to the curfew list to suppress looting in those areas.

Chile has increased deployment of troops to 14,000 across quake-hit areas in an attempt to quell clashes and restore order.

Meanwhile, international aid has been pouring into the quake-ravaged country. Food, water, tents, blankets and medical equipment are arriving at Santiago international airport as operation at the airport began to restore after terminals were damaged in the quake, disrupting incoming and outgoing flights.

Chile's neighboring countries also felt Saturday's mega quake, such as Peru. To learn a lesson from this disaster, Peruvian President Alan Garcia on Wednesday unveiled a national seismic prevention plan, since the country has a history of strong earthquakes.

The program aims to prepare residents who live in urban areas for possible consequences of an earthquake of great magnitude, Garcia said.

Apart from causing tsunamis worldwide, the massive earthquake might have changed entire Earth's rotation and shifted the Earth's axis, according to scientists at NASA of the United States.

They said the quake should have moved Earth's figure axis by about 3 inches (8 cm or 27 milliarcseconds) so that it might have shortened the length of an Earth day by 1.26 milliseconds.