Santiago, Chile (CNN) -- Aid poured in for Chile from home and overseas, with a local television station hoping to raise $27 million by Saturday and the United Nations pledging funds toward recovery efforts after a massive earthquake.

"Chile Helps Chile," a telethon that started Friday, runs until Saturday night, according to TV Chile's Web site. The site includes phone numbers and and e-mails for making donations in nearly 20 countries outside the South American nation.

Hundreds of people died when the 8.8-magnitude earthquake struck Chile last Saturday. The world's fifth-strongest earthquake since 1900 resulted in a tsunami that toppled buildings, particularly in the Maule region along the coast.

It's still unclear exactly how many people died.

Army divers have been searching the waters near the city of Constitucion for the bodies of as many as 400 tourists who were camping on an island during a summer festival.

"There were horrible screams. People calling out for us to go and rescue them. They were crying for help. But there was nothing we could do," local fisherman Agustin Diaz said.

Full coverage of Chile's earthquake

United Nations chief Ban Ki-moon on Friday pledged up to $10 million to support relief and recovery efforts during a two-day visit, where he met with Chilean President Michelle Bachelet.

"I am visiting this city with a deep sadness," Ban told reporters Saturday while in Concepcion. "Standing before this destruction, I can feel for your loss, your struggle.

"At the same time I am very grateful, very moved by such a strong determination," he added. "The leaders, the people on the ground, they are all united."

Ban also announced Friday a team effort between U.N. agencies and the Chilean government to determine the priority areas for funds, with emphasis on health, shelters, education and water. The secretary-general plans to bring the matter in front of the United Nations on his return.

Chileans proud to help out their own

The Chilean government has asked the United Nations for items such as field hospitals with surgical facilities, dialysis centers, generators, saltwater purifying systems, mobile bridges and field kitchens.

Chile endured two more strong aftershocks Friday -- the first a 6.0-magnitude earthquake and the other 6.6. They were the latest in scores of aftershocks that have hit in the past week.

Friday's aftershocks did not cause any known injuries or damage and no tsunami warnings were issued.

A six-member U.S. Agency for International Development disaster response team has been sent to Chile to assist with relief effort, said State Department spokesman P.J. Crowley.

Shocking scenes hours after quake

The United States has sent 71 satellite phones, plastic sheeting and two mobile water treatment units, the State Department said. Six more water treatment units are to arrive within a week. A field hospital and two C-130 aircraft to assist with moving supplies around the country have also been deployed.

The United States has also sent $1 million to the International Federation of Red Cross and Red Crescent Societies to aid their efforts.

Chile has announced three days of national mourning beginning Sunday. Every house has been authorized to hang the national flag in memory of those who perished.

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The death toll was revised downward Thursday as authorities reviewed discrepancies in the reported number of dead in the Maule region.

To limit confusion, Deputy Interior Minister Patricio Rosende read aloud the names of 279 Chileans whose bodies had been identified by Thursday evening. The new tally does not account for hundreds of unidentified victims.

"It takes months sometimes to compile the information, because one of the biggest problems in the affected areas is the lack of precision and uncertainty at the scene," Rosende said.

Despite the disaster, the Chilean Davis Cup tennis team will open competition Saturday in Coquimbo, Chile, against Israel. Team officials and players said they would be playing in honor of quake victims.

"It will be difficult, but we will do our best for our country," said player Fernando Gonzalez.