(CBS/AP) A powerful, magnitude 7.8 earthquake struck mountainous central China on Monday, killing five people when two primary schools and a water tower collapsed, state media reported.

The quake struck 57 miles northwest of the Sichuan provincial capital of Chengdu at 2:28 p.m. (0128 Eastern), the U.S. Geological Survey said on its Web site. It said the quake was centered about 6 miles below the surface.

Xinhua News Agency said Monday that more than 100 students were also injured in the quake. Chongqing is a large municipality next to Sichuan province.

A statement issued by the government in Aba prefecture of Sichuan province said buildings were cracked and some had collapsed. Mountain roads were damaged after the temblor struck Monday afternoon.

The official Xinhua News Agency said the area has a population of about 110,000 residents.

Phone calls to the area could not go through after the quake that was felt as far away as Thailand, Pakistan and Vietnam.

The joint UN-European Commission's Global Disaster Alert and Coordination System, or GDAC, warned that the impact could be high because the quake struck during the day when cars would be on roads and people in high-rise buildings.

"This earthquake has potentially a high humanitarian impact and the affected region has medium vulnerability to natural disasters," GDAC said in a statement on its Web site.

In the Chinese capital Beijing, about 930 miles away, office towers were evacuated, including the building housing the media offices for the organizers of the Beijing Olympics, which start in August.

Buildings swayed for more than two minutes but there were no immediate reports of damage or injuries. Frightened office workers and shoppers could be seen lingering outside buildings in the central business district.

It was an unintended emergency response for the organizers, and extreme caution appeared to be taken. Thousands of people rushed or were ordered out of office towers in Beijing's central business district, including the building housing The Associated Press. The people stood on sidewalks for about an hour, then filed back into the buildings.

"I've lived in Taipei and California and I've been through quakes before. This is the most I've ever felt. The floor was moving underneath me. At first I thought I was fainting. I looked down and the floor was moving," said James McGregor, business consultant who was having a meeting inside the LG Towers, a twin high-rise complex in Beijing's business district.

Cai Jinqing, a partner is Beijing Brunswick Consultancy, a financial communications company, was also inside LG Towers when the quake hit.

"I felt the room moving horizontally, It was very, very strong. I couldn't sit down," said the Beijing native.

In Shanghai, skyscrapers swayed and most office occupants went rushing into the streets.

Calls to emergency response numbers in Chengdu rang constantly busy on Monday. An eyewitness reached by phone in Chengdu said people flooded from buildings.

A reporter with state television said customers fell as they rushed out of restaurants in Chengdu. The report also said cracks could be seen on some older buildings in the city.

The area where the quake lies on the eastern edge of the Tibetan plateau where mountains rise sharply and the population density is generally thin.

In the Taiwanese capital of Taipei, 100 miles off the southeastern Chinese, buildings swayed when the quake hit. There were no immediate reports of injuries or damage.

The quake was felt as far away as the Vietnamese capital of Hanoi, where some people hurried out of swaying office buildings and into the streets downtown.