Two days after a devastating earthquake rocked central China, burying an estimated 40,000 people, rescue teams Wednesday raced against time to find survivors before their efforts turned into a body-recovery mission.

Rescuers reached the epicenter of the quake for the first time late Wednesday, scouring flattened mountain villages for victims and distributing air-dropped supplies to survivors.

Nearly 26,000 people are still buried in earthquake debris and another 14,000 are missing after the massive earthquake that struck China's Sichuan province.

The figures were announced by Xinhua News Agency on Wednesday and are in addition to the official death toll of 14,866 that Xinhua announced earlier in the day.

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Up the river from the quake-rattled town of Dujiangyan, Chinese troops were rushing to plug "extremely dangerous" cracks found in a dam.

About 2,000 troops were sent Wednesday to work on the Zipingku Dam, Xinhua reported, but the government later said that experts had inspected the dam and declared it safe, according to a statement broadcast on state TV and posted on the Sichuan government Web site.

Military helicopters dropped food and medicine to Chinese earthquake survivors who remained cut off Wednesday in remote mountain villages behind roads clogged by landslides.

As help began to arrive in some of the hardest-to-reach areas, some victims trapped for more than two days under collapsed buildings were still being pulled out alive. But the enormous scale of the devastation meant that resources were stretched thin, and makeshift aid stations and refugee centers were springing up over the disaster area the size of Maryland.

The official Xinhua News Agency quoted government officials as saying rescuers who hiked Wednesday into the city of Yingxiu in Wenchuan county — the epicenter of Monday's magnitude 7.9 quake — found it "much worse than expected."

The survivors "desperately needed medical help, food and water," Xinhua said.

The official death toll rose Wednesday to 14,866, Xinhua said, but it was not immediately clear if that number included the some 7,700 reported dead in Yingxiu.

The toll was expected to rise further once rescuers reach other towns in Wenchuan that remain cut off from the Sichuan provincial capital of Chengdu more than two days after the quake. Roads leading to Wenchuan from all directions were still being cleared of debris, Feng Zhenglin, deputy minister of railway and transportation, said in Beijing.

The death toll for Mianyang city was also confirmed at 5,430, up from 3,629, on Wednesday, Xinhua said, with more than 18,000 people there still thought to be buried under crushed buildings.

At a middle school Sichuan province's Qingchuan county where students were taking a noon nap when the quake demolished a three-story building, 178 children were confirmed dead in the rubble and another 23 remained missing, Xinhua said.

Storms that had prevented flights to some of the worst-hit areas finally cleared on Wednesday. Military helicopters were seen flying north over Dujiangyan, and Xinhua said two of them airdropped food, drinking water and medicine to Yingxiu.

Trains were on their way to Sichuan carrying quilts, drinking water, tents and military personnel, Ministry of Railways spokesman Wong Yongping said. All railways in the province were working except for a line where a 40-car freight train was trapped by a landslide in a tunnel and burned, he said.

Rescuers raced to save people trapped under flattened buildings.

A 34-year-old woman who was eight months pregnant was rescued after spending 50 hours under debris in Dujiangyan.

In the Beichuan region, a 3-year-old girl who was trapped for more than 40 hours under the bodies of her parents was pulled to safety, Xinhua said.

Rescuers found Song Xinyi on Tuesday morning, but were unable to pull her out right away due to fears the debris above her would collapse. She was fed and shielded from the rain until rescuers extricated her from the rubble.

Premier Wen Jiabao looked over her wounds, part of his highly publicized tour of the disaster area aimed at reassuring the public about the government's response and to show the world that the country is ready to host the Beijing Olympics in August. Wednesday's leg of the Olympic torch relay in the southeastern city of Ruijin began with a minute of silence.

Wen said some 100,000 troops and police had been dispatched to the disaster zone. He also visited a school Wednesday in Beichuan where two classroom buildings collapsed in the earthquake, including a school with 2,000 students that state TV said sustained "heavy casualties."

Twelve Americans were found safe near the epicenter of the quake.

A spokeswoman for the World Wildlife Fund said the 12 members of the wildlife group were reached by satellite phone earlier in the day. The team was near the world's most famous panda preserve in Wolong, whose pandas were reported safe Tuesday.

East of the epicenter in the town of Hanwang, the smell of incense hung over a crowd of sobbing relatives who walked among some 60 bodies wrapped in plastic, some covered with tributes of branches or flowers.

Nearby, rescuers in blue uniforms carried more bodies out of a makeshift morgue at the Dongqi sports arena. The dead appeared to have come from heavily damaged apartments and a school behind the arena, where people stood in stunned shock.

People from the town and surrounding areas packed into blue tents provided by disaster relief officials. A clock tower in the town center had stopped at 2:27, the time the quake hit.

The Mianzhu No. 3 Hospital was obliterated, and the seven-story main Hanwang Hospital collapsed, its third floor suddenly smashing to the ground. People on the upper floors climbed out on bed sheets tied together.

Surviving medical staff set up a triage center in the driveway of a tire factory, but could only provide basic care.

"The first day hundreds of kids died when a school collapsed. The rest who came in had serious injuries. There was so little we could do for them," said Zhao Xiaoli, a nurse at Hanwang Hospital, who described herself as "numb."

Emergency vehicle sirens sounded every few minutes. An ambulance drove in, delivering a man pulled from the rubble and covered in dust.

"There will be a lot more people. So many still haven't been found," said Zhao.

Residents complained that delays in aid had caused more deaths in the immediate aftermath of the quake.

Zhang Chuanlin, a 27-year-old factory worker, said his 52-year-old mother was trapped while watching television with her friend. No rescue workers were around so he started to dig by himself.

"No one was helping me and then two strangers came and dug through the rubble. They found her an hour later," he said. "When they pulled her out I couldn't look, I just couldn't look when they pulled her out."

A man who gave only his surname Li said he had suffered a double tragedy. His wife was killed while watching TV with Zhang's mother and his daughter died when her school collapsed.

The child did not die right away and could be heard saying, "Please help me daddy, please rescue me," right after the earthquake, he said, but there were no authorities to save her.

The Associated Press contributed to this report.