UN Secretary General Ban Ki-moon, in blue, inspects an earthquake-damaged area in Concepcion. (Aliosha Marquez/Associated Press)

UN Secretary General Ban Ki-moon toured quake-damaged areas of Concepcion and the nearby port city of Talcahuano on Saturday as the first shipment of United Nations food aid arrived in Chile.

The consignment of 35 tonnes, unloaded in Concepcion, is the first part of a shipment that should help feed 35,000 children over the next five days, World Food Program representative Francisco Espejo said.

Ban arrived in Chile's capital, Santiago, on Friday for a two-day visit to assess damage from the 8.8-magnitude earthquake, which struck Feb. 27 and left coastal towns swamped by the tsunmai that followed. He pledged $10 million US from a UN fund for quake relief.

Appearing outside one of Concepcion's destroyed buildings, the UN leader said it's time for people around the world to show their support.

"Your people were generous enough to rush to Haiti when it was hit," he said. "Now it is the moment for the international community to stand with the Chilean people. I can feel all this, for your loss, for your struggle."

Pre-dawn aftershocks

Around 4 a.m. Saturday, a series of aftershocks shook buildings in Chile, causing buildings to sway and sending people running into the streets.

The U.S. Geological Survey reported the tremors ranged in magnitude up to 5.1, weaker than a series of aftershocks Friday which had magnitudes ranging from 6.3 to 6.8.

At one of the rare supermarkets that haven't been looted in Concepcion, people were rushing to fill up their carts on Saturday.

"It was so strong, but we're starting get used to these tremors," one woman in the lineup said when asked about the aftershocks. "There are so many, we wonder sometimes if it's our imagination or not."

A woman smiles as she leaves a supermarket with bags filled with supplies she just bought in Concepcion. (Natacha Pisarenko/Associated Press)"But many others say these rumblings are getting to them," said CBC's Connie Watson, reporting from Concepcion. "They're feeling stressed and nervous all the time now, and that stress doesn't let up, because as soon as darkness falls, they join with their neighbours, putting up barricades to guard against looters."

Chile has been rattled by more than 200 aftershocks since the devastating earthquake struck.

On Friday, the government revised its estimate of the number of people killed down to 279, backing away from earlier estimates that put the death toll at 802.

The quake unleashed a tsunami that hit coastal towns, leaving behind piles of debris and tons of rotting fish. The mess will contribute to infections, mayor of the port city of Talcahuano, Gaston Saavedra, has warned.

The government faces other health-care problems. Looting of pharmacies has made medicine scarce for people suffering from diabetes, hypertension and psychological illnesses.

Thirty-six hospitals were heavily damaged or destroyed in the quake.

With files from The Associated Press