Hong Kong - It is a scene to make the most ardent animal-hater wince. Pathetically unaware that it is just 30 seconds from death, a dog stands wagging its tail expectantly as three men carrying long bamboo poles edge towards it on a dusty village track.

There is a second's pause before the first blow, delivered from behind, lands on the dog's neck. It yelps in surprise and pain then scrambles back and forth in panic as the poles crack down again and again, shattering its spine.

To the laughter of his colleagues, one man steps forward and delivers the coup de grace: a deadly blow that cracks the skull.

This is rabies control, China-style. In the space of just 10 days in May, 20,000 stray dogs were slaughtered in Hanzhong, central China, and surrounding towns and villages in response to a rabies outbreak that has led to the death of eight people since March.

Secretly filmed images shot by animal lovers in this city at the heart of Shaanxi show gangs of men roaming the streets with poles and boulders, dead dogs piled up on wooden carts, the bodies of animals lying mutilated and bleeding by roadsides.

"I watched that video with absolute disbelief," said Jill Robinson, founder of the Hong Kong-based Animals Asia Foundation which is supporting groups in China campaigning for an end to the culls.

It was not the first time dogs have been slaughtered on the mainland to eradicate a rabies threat. A nationwide cull took place in the months leading up to the Olympics, sparking international criticism.

What made the Hanzhong cull unusual was its speed, scale and savagery. In rural villages, men who one week lived in friendly cohabitation with communities of semi-stray dogs were transformed into their executioners.

One victim was the pet dog of 55-year-old housewife Bai Lihe, among 300 dogs culled in Xiayishui village. "Doudou was small and he never bit," a tearful Bai told her local newspaper. "I had just had him vaccinated against rabies and they still clubbed him to death."

A neighbour, 26-year-old Bai Xinpeng, described how he had locked himself in his house with his three pet dogs. "There used to be nearly 400 dogs in this village. Now it's hard to spot even one," he said.

Dang Zhengqing, party secretary for the county covering Xiayishui village, explained the official rationale for the cull, saying it had ended with the deaths of all stray dogs in the area and pronouncing: "People are safer now from the (rabies) epidemic.

"I understand the public anger but we don't kill owned dogs on leash. The culling is extreme but necessary to combat the deadly epidemic. All lives are equally important but we decided to sacrifice dogs for human health."

But even in China's state-run newspapers, the necessity of the slaughters is coming under question. Tan Xiaodong, a public health professor at Wuhan University, told the China Daily newspaper there was "no justification" for them.

"In addition to dogs, animals including cats and bats can also cause rabies. It's impossible to kill them all," he said. "To eradicate the disease, what is needed is long-term proper management and oversight over dog keeping."

It is an argument that appears to be gaining in weight as the voices of dog owners on the mainland become gradually stronger and more confident. Delegations of animal lovers have travelled to Hanzhong to press for more humane methods of disease control.

"Two years ago, this wouldn't be happening," said Robinson. "Now, people have found a voice and they are using it. People are standing up and becoming the voices for these defenceless animals."(dpa)