Chinese rescuers funnelled relief supplies to the epicentre of a powerful earthquake for the first time yesterday, scouring flattened mountain villages for tens of thousands of missing and buried victims amid fears the death toll of nearly 15,000 would soar far higher.

Some 2000 soldiers rushed to plug cracks in the Zipingpu Dam upriver from the earthquake-hit town of Dujiangyan, the official Xinhua News Agency said. But late last night, the government pronounced the Zipingpu Dam safe after it was inspected by experts.

He Biao, the director of the Aba Disaster Relief headquarters in northern Sichuan, said there were also concerns over dams closer to the epicentre.

"The most dangerous problems are several reservoirs near Wenchuan," he said.

He added that problems at the Tulong Reservoir on the Min River could lead to collapse. "If that happens, it would affect several power plants below and be extremely dangerous," he said.

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

The hunt was still on for 19 British tourists who have yet to be accounted for. The British ambassador to China, Sir William Ehrman, flew in to the earthquake-hit region of Sichuan yesterday to help co-ordinate the search for missing British nationals.

The Foreign and Commonwealth Office (FCO) said it was working around the clock to track down "a number" of British citizens.

Among those unaccounted for are British holidaymakers who are touring with the Travel Collection, a company owned by Kuoni. They were on a visit to Wolong panda reserve, in Wenchuan county, when the earthquake struck.

With hospitals levelled, doctors and nurses were forced to treat survivors in the street. Helicopters buzzed overhead, dropping food and medicine to isolated towns - part of the mobilisation of 100,000 troops and police for the relief effort.

Government officials said rescuers who hiked into the city of Yingxiu in Wenchuan county - the epicentre of the quake - found only 2300 survivors in the town of about 10,000, with another 1000 badly hurt.

The official death toll rose to 14,866, but it was not immediately clear if that number included the 7700 reported dead in Yingxiu. In Sichuan province alone, another 25,788 people were buried and 1405 were missing, provincial vice governor Li Chengyun said.

Unlike previous natural disasters in China, official media have reported prominently on the quake. Scenes of destruction and death have been shown, along with prominent focus on Premier Wen Jiabao, who has overseen the rescue work.

Wen was there when one three-year-old girl trapped for more than 40 hours under the bodies of her parents was pulled to safety yesterday in Beichuan region.

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.

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

"It's a miracle brought about by us all working together," said Sun Guoli, fire chief of the provincial capital Chengdu.

A team of British experts from the International Rescue Corps (IRC) have arrived in Hong Kong and are awaiting visas before travelling to the region. The IRC has sent a team of 10 highly trained volunteers from across the UK, including Scotland.