Vietnamese authorities have reportedly buried several thousand cats, some believed to be still alive, after securing them from smugglers.

An estimated three tonnes of live cats, shoved into bamboo crates, were seized from a truck late Tuesday (3 February) in the Vietnamese capital Hanoi.

The cats were smuggled into Vietnam from China to serve the country's illegal cat-meat trade.

In accordance with Vietnamese law on smuggled goods, the cats had been buried, a police officer told AFP News on Wednesday (4 February).

"The cats were from China, with no official origin papers and no quarantine. Several of them had died," a Vietnamese police officer from the Dong Da district environmental told AFP News on condition of anonymity.

"There was a terrible smell that could affect the environment and carried risks of future diseases.... Therefore, we culled them by burying them."

The officer declined to reveal how many of the cats were alive at the time of burial.

Several animal rights groups, who urged authorities to spare the cats, fear many were buried alive.

The Asian Canine Protection Alliance called for an end to the, "practice of inhumane killing of trafficked animals," in a statement on Wednesday (4 February).

"Our request for any visual evidence of their fate has been denied," said the group.

Vietnam is known to follow a similar practice of routine disposal on other smuggled animals, including chickens.

Cat meat, referred to as 'little tiger' locally, is known to be a delicacy in Vietnam.

Despite Vietnam banning cat meat consumption, several dozen restaurants are still serving cat meat.

Pet owners mostly keep their cats indoors fearing they will be stolen and smuggled into the illegal market.

Vietnam cats
Seized cages of live cats transported in a truck in Hanoi seen on January 27, 2015. Getty Images