"We were in the process of filming a man about to be pulled out after hours of digging and the rescue team had to abandon him and run."
The Xinhua news agency warned that a lake, formed by landslides blocking a river, "may burst its bank at any time".
However, the authorities later said the city was not under threat from the water.
Our correspondent saw troops returning to the city to resume the rescue effort, but no civilians.
Those inhabitants who had stayed in the city after the quake, or had returned to check on their property or search for loved ones, appeared now to be staying on the surrounding hillsides.
"It is not surprising," he says. "This entire community has been shaken to its core, they are surrounded by unstable buildings which threaten to topple at any moment, and the people have been deeply traumatised by what has happened."
The Chinese government has organised a massive search and rescue effort. It released figures on Saturday demonstrating the scale of the operation.
It said 198,347 people had been recorded injured, not just in Sichuan, where the quake struck, but in Gansu, Shaanxi, Chongqing, Hubei, Henan, and Guizhou provinces.
A woman found under the rubble some 124 hours after the quake
On Friday 26,801 personnel were sent on rescue and relief missions, while 34,000 medical staff were "in the frontline", it said.
During the day 2,538 people were recovered from the ruins - 165 of whom were still alive.
It said some 181,460 tents, 220,000 quilts, and 170,000 cotton-padded garments had been despatched to the disaster area.
Rescue teams from South Korea, Singapore and Russia have joined Japanese and Taiwanese experts taking part in the massive search.
The specialist teams are equipped with sniffer dogs, and fibre-optic cameras and heat sensors to detect people buried under the rubble.
But experts say the chances of finding people alive are diminishing, and increasingly it is dead bodies which are being retrieved.
The authorities have resorted to burying the bodies in mass graves.
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