Officials at Sochi city hall have ordered more stray dogs to be exterminated over the Russia Winter Olympics.

Speaking to the Associated Press, the head of a pest control company that regularly puts down stray dogs said officials have asked more to be killed for the duration of the Games.

Alexei Sorokin, director general of pest control firm Basya Services, said they have been instructed to catch and dispose of any stray dogs in the city area.

He did not say how the dogs were killed, whether they were shot or poisoned, or what they do with the carcasses afterwards. He also refused to say how many dogs are killed each year, calling it a "commercial secret".

However, some animal rights groups say over 2,000 stray cats and dogs were killed in 2013, with charities filming evidence of animals being killed in the street at night.

Stray dogs have been a problem in Sochi for many years, with some of them displaying aggressive behaviour and biting children. Animals abandoned by their owners in Russia are often unneutered, as this can be expensive, so they breed quickly and numbers multiply fast.

\"These dogs are biological trash.\" Alexei Sorokin

A stray dog was recently seen at the rehersal for the opening ceremony, which is due to take place on 7 February, Sorokin said.

"A dog ran into the Fisht Stadium, we took it away. God forbid something like this happens at the actual opening ceremony. This will be a disgrace for the whole country."

Speaking to ABC News, he added: "I am for the right of people to walk the streets without fear of being attacked by packs of dogs. Let's call things by their real name. These dogs are biological trash."

Many dogs congregate around building sites as they are often fed by workers. Sergei Krivonosov, a lawmaker from the Krasnodar region, said he supports the extermination contract, saying it was the nation's "responsibility".

"[It is Russia's] responsibility to the international community and that their elimination is the quickest way to solve this problem."

Last year, after a contract to kill stray dogs was announced, animal rights groups protested and Sochi authorities said it would stop the cull and build more animal shelters. However, there is no evidence to date to show this work has been carried out.

Officials were also extensively criticised for the inhumane methods used to kill the animals, with many beaten and stabbed to death by "dog hunters".

Condemning the practice of killing strays, a Peta (People for the Ethical Treatment of Animals) spokesman said: "Although Russia has reportedly spent more than $50bn (£30.6bn) in preparation for hosting the Winter Olympics, it's the animals of Sochi who are paying the ultimate price, as stray dogs are being rounded up and killed in cruel ways in an apparent effort to present the world with a glamorous image of Russia.

"This cruel killing programme will do nothing to provide a long-term solution to the stray-dog population. Just one female dog and her offspring can produce 67,000 puppies in only six years, so the only way to get to the root of the overpopulation crisis is to stop more puppies from being born by implementing a comprehensive spay-and-neuter programme.

"We urge sports fans to contact their Russian embassy and demand an end to the massacre, which is tainting this sporting celebration with the blood of thousands of innocent animals."