BEIJING -- A major earthquake measuring 7.8 on the Richter scale jolted Wenchuan County of southwest China's Sichuan Province at 2:28 p.m. Monday, the State Seismological Bureau said, revising a previous figure of 7.6.

The epicenter of the quake was located 31.0 degrees north latitude and 103.4 degrees east longitude, the bureau said.

President Hu Jintao instructed to do utmost efforts to rescue and treat the victims, and Premier Wen Jiabao is on the way to Sichuan to direct the rescue efforts, according to a Xinhua report.

It was not immediately clear if there were any casualties or damage from the tremor.

"We felt continuous shaking for about two or three minutes. All the people in our office are rushing downstairs. We're still feeling slight tremblings," said an office worker in Chengdu.

With a population of 111,800, Wenchuan lies in southeast part of the Tibetan-Qiang Autonomous Prefecture of Aba, 146 km to the northwest of Chengdu, provincial capital of Sichuan.

Wenchuan is home to the Wolong Nature Reserve, China's leading research and breeding base of the endangered giant pandas.

In Beijing's financial district, many workers poured from their buildings but there were no visible signs of damage. The subway system was unaffected.

"People were shouting 'get out, get out', so we all ran out of our dorm," said a student surnamed Zhang at a university in nearby Chongqing.

Xinhua reporters in many other parts of China also reported tremors. Reporters in Chengdu said they saw cracks on walls of some residential buildings in the downtown areas, but no building collapsed.

The telecom networks in Chengdu and Chongqing cities broken down for a while after the quake. People complained they were unable to have phone calls on the fixed line or the mobile.

The quake was also felt in Zhengzhou, capital of central Henan Province, where people rushed out of homes and offices and took to the streets.

Many said they felt dizzy and saw the pendant lamps on their ceilings swinging back and forth.

In Lanzhou, capital of the northwest China's Gansu Province, the quake sent many parked cars by the roadside buzzing. Xinhua reporters in Yinchuan, capital of Ningxia Hui Autonomous Region, said they felt the office building rocking back and forth for about four minutes.

A retiree in Leshan City of Sichuan Province said over the telephone that a wall in her garden collapsed, while a repairman in Chongqing saw the ceiling of his factory shamble and alarmed the staff, who soon left the building. In Shanghai, people were evacuated from office buildings in Hongqiao and Nanjing Road.

An earthquake measuring 3.9 on the Richter scale jolted Tongzhou District in east Beijing at 2:35 p.m. Monday. The quake's epicenter was located 39.8 north latitude and 116.8 east longitude, according to the State Seismological Bureau.

In Shanghai, people were evacuated from office buildings in Hongqiao and Nanjing Road.
Mobile phones in Chengdu and Chongqing could not be reached for a while on Monday afternoon.

---China Daily