(May 15) (Bloomberg) -- China's army is sending an extra 30,000 troops to southwest Sichuan province as disaster workers try to reach tens of thousands of people trapped under debris after the strongest earthquake in more than half a century.

Ambulances and double-decker buses packed with rescue workers streamed along the main highway from Chengdu, the capital of southwest Sichuan province, to Dujiangyan, the center of relief operations. The 7.9-magnitude quake three days ago killed almost 15,000, injured about 65,000 and left at least 30,000 people buried, the official Xinhua news agency said.

The troops are being sent to join about 50,000 soldiers and armed police already working to rescue victims trapped under rubble from collapsed schools and offices, Xinhua said. About 100,000 relief workers, including soldiers and medical teams, are working in the affected areas, Prime Minister Wen Jiabao said on state television.

``Time is life,'' Wen told survivors and rescuers during a visit to Beichuan County yesterday, where workers are fighting to rescue more than 1,000 students and workers trapped after Beichuan Middle School collapsed. ``This is very important to let them know rescuers are trying to save them. Even though there is only a slim chance of survival, we should not lose hope.''

Troops, paramilitary and medical teams have now reached Wenchuan, the nearest city to the epicenter of the quake and along the highway from Dujiangyan.

Trapped Under Rubble

Tents were pitched in soccer fields and vehicles waved through toll booths without charge on the highway into Dujiangyan. On the outskirts of the town, local residents provided food and water from makeshift stands. Some complained about delays in helping survivors.

``The local government is nowhere in sight,'' Pu Juan, a resident, said on Jincheng Road in Dujiangyan. ``We are very disappointed that there's been no action. The only help we've received has come from the initiatives of our neighbors.''

Hundreds of students are still trapped under the rubble at Juyuan Middle School in Dujiangyan, according to a security guard who would only gave his last name, Chen. The bodies of four children, covered in blue bed sheets, lay on salvaged classroom doors in a muddy tented area where relatives were brought to identify them.

Searching for Bodies

Rescue workers are searching for 30 missing patients and employees at Dujiangyan Hospital. Eighty bodies have been recovered and 20 survivors pulled from the rubble of the hospital, which collapsed after the quake.

``The scale of the disaster is something we have never experienced before,'' Liu Junlin, the Communist Party secretary of Dujiangyan, said in an interview at a sports stadium under construction. ``We are exhausting all our resources to rescue trapped people and save lives.''

In Beichuan County, rescue workers pulled a 3-year-old girl out of the rubble from under the bodies of her dead parents. The girl had survived, with serious leg injuries, after being buried for more than 40 hours, Xinhua reported.

In the province's Qingchuan County, more than 201 students are now confirmed dead after the school dormitory where they were taking an afternoon nap collapsed during the quake, Xinhua reported. An estimated 89 students are still buried while a further 139 escaped, the agency said.

Dam Reports

Some 2,000 troops have been sent to work on the Zipingpu Dam, upriver from Dujiangyan, where cracks have been detected, the Associated Press said, citing state media. The quake caused the 760-megawatt hydropower generating unit at Zipingpu, 9 kilometers upstream of Dujiangyan, to collapse, the provincial government said, according to Reuters.

Xinhua later cited a spokesman for the operators of the dam as saying that reports of cracks were rumors and that experts examining the structure confirmed that it was ``safe and stable.''

The candor about the quake and access to Chinese leaders contrasts with the media lockdown during Tibetan riots two months ago, when the leadership stayed at home and sealed off the region. Wen's rapid response also signals a determination to avoid missteps that followed January's deadly snowstorms and the 2003 SARS outbreak and to shore up support for the ruling Communist Party.

``There's very little effort to control information,'' said Huang Jing, a visiting senior fellow at the National University of Singapore East Asian Institute. ``Compared with the Tibet crisis, it looks almost like two governments.''

More Aftershocks

Aftershocks continued to rattle the region, disrupting search-and-rescue efforts and keeping survivors huddled in the rain outside shattered buildings. A 5.4-magnitude quake that was 10 kilometers deep hit yesterday at 10:54 a.m. local time, the U.S. Geological Survey said on its Web site. Xinhua said that 18 quakes measuring above 5 have been monitored since the initial shock on May 12.

Rain that hampered rescue efforts for the past three days eased and eight planes took off to drop supplies on Wenchuan and other areas, China Central Television said. The weather forecast in the affected region is for cloudy conditions for the next two days, according to the China Meteorological Administration's Web site.

Flights to Sichuan are restricted to relief supplies and authorities called on passengers to avoid flying in central and southwestern China. The rail link between Baoji in Shaanxi and Chengdu is still closed, the Ministry of Railways said. Chinese shipments of steel, copper and other commodities have been disrupted by the quake.

The quake was the world's strongest since an 8.5-magnitude temblor struck Indonesia in September, according to the USGS. It was the most powerful to hit China since a magnitude-8.6 quake struck Tibet in 1950, killing 1,526 people. A 7.5-magnitude quake killed 250,000 people in northeastern China's Tangshan in 1976, according to the USGS.

Editor: Haijing Qu