Dujiangyan — The first rescue workers reached the epicenter of the Chinese earthquake yesterday and discovered a scene of devastation with tens of thousands missing, many presumed dead.

A team of 1,300 soldiers and medical staff arrived on foot in Wenchuan, the county where the 7.9 magnitude earthquake struck just before 2:30 p.m. on Monday.

In Yingxiu, a town of 12,000 people, only 2,300 had been found alive, the director of the prefecture’s emergency office, He Biao, told state television. In another southwestern town, 80% of homes had collapsed, along with roads and bridges, and altogether in the county 60,000 people were unaccounted for, he said.

“They could hear people under the debris calling for help, but no one could, because there were no professional rescue teams,” he said.

Among the missing are a coach party of 19 Britons in Wenchuan. The county contains the Wolong Nature Reserve, home to the world’s largest collection of captive giant pandas. The Britons were traveling to Wolong from Chengdu, according to Kuoni, their tour operator, which was trying to contact them last night. The Foreign Office was said to be preparing to send in a rapid response team to look for them.

Another 100 British tourists in the region were reported to be safe, while the Chinese authorities said they had no reports of foreign casualties.

No major teams with equipment have been able to reach Wenchuan, as roads through the mountainous passes are broken and blocked by landslides. While rescuers struggled to help those trapped in the mountains, in the plains to the south efforts were under way to pull any survivors from the rubble of collapsed buildings.

The People’s Liberation Army said 20,000 troops were working in the affected region and 30,000 more were on their way. But, though paratroops have been ordered to drop into Wenchuan, helicopter operations are being hampered by heavy rain and fog across much of the area.

“What we most need is medicine,” Mr. He said. “There is no medicine, there are no doctors, and after such a long time, no food.”

British agencies including Oxfam and Save the Children are helping with the relief effort, sending expert teams to the region. Britain’s Foreign Secretary, David Miliband, praised China’s “exemplary” response to disaster, in comparison to the “callous” response of the Burmese authorities.

Even if a majority of the missing are found safe and well, the number of deaths is sure to escalate well beyond the 12,000 so far confirmed.