根據大陸地理資料指出，汶川縣位於四川省西北部、阿壩州境東南部的岷江兩岸，是阿壩州的南大門，有川西鎖鑰和西羌門戶之稱，是大禹的故鄉。該縣境 海拔1326米，距省會成都159公里，東西寬84公里，南北長105公里，總面積4084平方公里。界於北緯30°45′～31°43′與東經102° 51′～103°44′之間。

其中，西南部開發較少，不過著名的國家級自然保護區臥龍大熊貓自然保護區座落此區，大陸於1970年正式建為臥龍特別行政區，並設有世界首屈一指的大熊貓研究中心。

大陸資料顯示，目前世界上野生大熊貓僅存1590隻左右，主要分布在四川盆地周圍的崇山峻嶺之中。位於汶川縣西南部的臥龍自然保護區是中國最大的大熊貓自然保護區，區內擁有野生大熊貓150多隻。

Many more are feared killed and injured in other parts of the country after the quake, which had a magnitude of 7.8, struck at 1428 local time (0628 GMT).

At least 50 bodies have been recovered from the rubble of a school where an estimated 900 students were buried.

President Hu Jintao has urged “all-out” efforts to rescue victims.

The epicentre of the earthquake was about 92km (57 miles) from Chengdu, Sichuan’s provincial capital.

Because the earthquake struck in the middle of the day, it is feared that many schoolchildren may be among the victims.

Cries for help

One of the worst-hit areas appears to be Beichuan county, part of the Mianyang city municipal area, about 50km from the epicentre.

Some 80% of buildings there were reported to have been destroyed, leaving between 3,000 and 5,000 people dead and up to 10,000 injured.

Meanwhile hundreds of people were reported to have been buried in two collapsed chemical plants in Shifang in Sichuan, and at least five other schools were reported to have collapsed.

And there are fears the death toll could turn out to be much higher once the damage in Wenchuan county – the epicentre – is assessed, says BBC China analyst Shirong Chen.

The area is very rugged, full of mountains and valleys and a number of roads are connected with bridges from one mountain top to the next, he says.

RECENT CHINA QUAKES March, 2008: 7.2 quake in Xinjiang – damage limited February 2003: 6.8 quake in Xinjiang – at least 94 dead, 200 hurt January 1998: 6.2 quake in rural Hebei – at least 47 dead, 2,000 hurt April 1997: 6.6 quake hits Xinjiang – 9 dead, 60 hurt January 1997: 6.4 quake in Xinjiang – 50 dead, 40 hurt In pictures: China earthquake ‘Buried teenagers crying for help’ How earthquakes happen

Wenchuan county is also home to the Wolong Nature Reserve, China’s leading research and breeding base for endangered giant pandas. The centre could not be reached by phone, it was reported.

Chinese Premier Wen Jiabao, who flew to Chengdu immediately, said China needed “calm, confidence, courage and strong leadership”.

“We will definitely overcome this major disaster,” he promised.

US President George W Bush expressed condolences to victims’ families, while Japan offered to send aid.

There were harrowing reports from the scene of a school collapse in Dujiangyan city – about 100km (60 miles) from the epicentre – where 900 students were buried and 50 dead.

Teenagers buried beneath the rubble of the three-storey Juyuan Middle School building were struggling to break free, while others were crying out for help, state news agency Xinhua reported.

Parents were watching as cranes excavated the site. Villagers rushed to help with the rescue.

Two girls said they escaped because they had “run faster than others”.

Fast response

Dozens of aftershocks have been reported since the quake, which was felt in Beijing, 1,545km (960 miles) away, and the Thai capital Bangkok, 1,800km (1,200 miles) away.

It was the strongest to hit Sichuan province in more than 30 years, Xinhua said.

The province is the most populated part of China – home to 87 million people.

State television said the quake had not caused major damage to Chengdu, which has a population of more than 10 million people, or to the nearby Three Gorges Dam.

Troops and helicopters have been sent to help with relief work.

The BBC’s Quentin Somerville says this is probably the the most significant natural disaster to hit China in recent memory, but that the Chinese army has a good record of mobilising and getting people to safety.

He also says it is one of the most open and speedy responses to an emergency he has ever seen from Chinese state media.

The quake was felt as far away as Beijing, he says, meaning millions of people will feel connected to the disaster and will be watching TV screens closely to see how the government responds.