Aid supplies began to arrive in Indonesia on Friday as rescue teams continued to search for anyone trapped beneath piles of rubble left by a powerful earthquake.

The country's Disaster Management Agency said as of Friday, 715 people have been confirmed dead and 2,400 hospitalized since the 7.6-magnitude earthquake struck western Indonesia on Wednesday.

But John Holmes, the United Nation's humanitarian chief in New York, said figures it had received from Indonesia suggested at least 1,100 people had died.

U.S. President Barack Obama called Indonesian President Yudhoyono on Friday morning to express his condolences for the death and destruction caused by the earthquake in West Sumatra, and to offer U.S. assistance in the recovery effort.

Aid for thousands of survivors began trickling in and specialist rescue teams from various countries arrived in Padang -- a coastal town of 900,000 people, and the capital of West Sumatra province.

Russia sent two planeloads of supplies, as well as doctors and nurses. Also donating millions in aid and assistance were the governments and charities of Australia, Britain, China, Germany, Japan, the European Union, Malaysia, Singapore, South Korea, Switzerland and Denmark, according to Indonesian officials.

But Indonesian officials say a lack of heavy digging equipment and power blackouts were hampering the search for survivors.

Glimmer of hope

Earlier on Friday, rescuers pulled two women -- a student and a teacher -- alive from the rubble of a collapsed college, nearly two days after the disaster struck.

It was a glimmer of hope in a devastated region, in which nearly 3,000 people may still be trapped under the rubble, according to Indonesia's Health Ministry.

Rescuers are frantically searching for more survivors after cries of help were heard from under what was formerly the Ambacang Hotel. According to Japan's Kyodo news agency, a Japanese rescue team was leading the effort to free those trapped.

"We heard some voices of people under the rubble, but as you can see the damage is making it very difficult to extricate them," said rescue team spokesperson Gagah Prakosa.

The student pulled from the rubble of the collapsed Foreign Language School of Prayoga was identified as 19-year-old Ratna Kurniasari Virgo, an English major sophomore.

"She is fine, conscious and does not have any life-threatening injuries," Nining Rosanti, a nurse at a hospital, told The Associated Press.

Television footage showed her carried on a stretcher before she was taken to hospital, where she is being examined and treated for a possible broken leg.

The teacher, Susi Revika Wulan Sari, spent 48 hours pinned down by the rubble as she lay surrounded by the dead bodies of her students. But she appeared happy as rescue workers carried her away on Friday.

"She was conscious. Only her legs and fingers are swollen because she was squeezed," the institute's director, Teresia Lianawaty, told the Associated Press. "Thank God! It is a miracle."

Cut off

While rescue efforts continued in the capital on Friday, the extent of the devastation in Pariaman - a small city about 80 kilometres to the north and home to about 370,000 people - is unknown.

The town is cut off, and locals were left to fend for themselves. The Associated Press reported most structures there had been levelled, and locals were using shovels and their bare hands to clear landslides and dig out bodies. It was unclear on Friday how many people died.

Indonesia lies on a major geological fault zone and experiences dozens of quakes every year. Wednesday's quake was the deadliest since May 2006, when more than 3,000 people died in the city of Yogyakarta.

Indonesian Finance Minister Sri Mulyani said the government has allocated $25 million for a two-month emergency response.

U.S. President Barack Obama, who spent part of his childhood in Indonesia, pledged $3.3 million in immediate assistance.

"Indonesia is an extraordinary country that's known extraordinary hardship with natural disasters," he said.

With files from The Associated Press