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China warned Saturday that the death toll from a massive earthquake two weeks ago could take a major leap and pass 80,000, suggesting the government may be giving up hope of finding more survivors.

But rescuers rushed anyway to reach 24 coal miners who officials said were trapped in three mines by the disaster, though it was not known if the miners were alive.

"We have had the miracle in the past that a miner was found alive after being trapped underground for 21 days," Wang Dexue, the deputy chief of the government's work safety department, told a news conference in Beijing. "We are carrying out rescue work on the assumption that they are still alive. We absolutely will not give up."

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Wang gave no further details of the trapped miners. China's mines are the world's deadliest, with explosions, cave-ins and floods killing nearly 3,800 people last year.

Meanwhile, U.N. Secretary-General Ban Ki-moon made a brief visit Saturday to one of the hardest-hit towns, Yingxiu — a helicopter ride that offered a rare bird's-eye views of the destruction wrought by the 7.9-magnitude quake on May 12.

The mountains in central Sichuan province showed huge tracks of naked earth from landslides. Layers of mud covered fields. Rivers churned brown. Yingxiu itself was largely piles of rubble, and the buildings left standing had caved in, giving the surreal impression that they had melted.

The State Council, China's Cabinet, said Saturday the latest confirmed death toll for the quake — China's biggest disaster in three decades — was 60,560, with 26,221 people still missing.

Premier Wen Jiabao, on a return visit to the quake zone to accompany Ban, warned the toll could go much higher.

"It may further climb to a level of 70,000, 80,000 or more," Wen said, standing amid the rubble in Yingxiu. The jump could occur as the number of missing are added to the number of dead.

About 15 minutes before Wen started talking, yet another minor aftershock rumbled.

Ban, who came to China directly from cyclone-stricken Myanmar, promised the U.N. would help with reconstruction and that it was waiting for China's assessment of what was needed.

"If we work hard, we can overcome this," Ban said, with Wen standing at his side. "The whole world stands behind you and supports you."

The secretary-general left China later Saturday and was to attend an aid donors conference in Myanmar for cyclone victims on Sunday.

About 4,800 of Yingxiu's 18,000 people were killed in the quake, a military officer told Ban during a tour. Reporters could see government workers in hooded white protective suits spraying disinfectant on the rubble.

Underscoring doubts that more survivors would be found, Wen said the government's focus had shifted from rescue to rebuilding.

"Previously our main priority was the search and rescue of affected people," Wen said. "Our priority now is to resettle the affected people and to make plans for post-quake reconstruction."

It won't be easy. The quake destroyed more than 15 million homes, Wen said. He said the government needed 900,000 tents and urged Chinese manufacturers to make 30,000 a day.

As the government grappled with the task of rebuilding — a process Sichuan Vice Governor Li Chengyun has said could take three years — it also watched for a variety of secondary disasters.

Experts searched for 15 radiation sources buried in the rubble, although they said there were no leaks or public health risk. And survivors left flood-risk areas downstream from rivers that had been dammed by landslides.

With their water pooling and the rainy season coming, the "quake lakes" could breach the earthen barriers and sweep down already fragile valleys.

Meanwhile, some 10,000 medical workers have been dispatched to prevent disease outbreaks.

"The second major challenge facing us is epidemic prevention and control," Wen said, adding that no outbreaks had been reported so far.

The premier also promised that China would continue its openness about the quake, in which the government has accepted foreign relief teams and allowed Chinese media to report in relative depth on the disaster.

"From the very beginning of the disaster relief, we put people's lives above all," Wen said, "We have adopted an open policy because we think it was not only the disaster for Chinese people, but the people of the world. Our spirit of putting people above all and our open policy will not change."

Also Saturday, eight pandas reached Beijing safely after a long journey from their damaged reserve near the quake's epicenter. The pandas will spend the next six months at the Beijing Zoo on a special Olympics visit that was planned long before the quake.

The pandas' home at the world-famous Wolong reserve was badly damaged by the quake and five staff members were killed.

The pandas have been closely watched because they seemed nervous after the earthquake, sometimes eating and sleeping less. But the pandas appeared lively after they were moved into their exhibit space at the Beijing Zoo on Saturday evening, even putting their paws on the glass separating them from the media and the public.