Alina Orlova was held in the Russian city of Vladivostok where she was waiting for a connecting flight between her home in Khabarovsk to St Petersburg.
The 17-year-old and pal, identified only as Kristina K., are accused of posting photographs and videos of themselves torturing and killing cats and dogs for “bloodlust”.
The horrific images show one dog nailed to a wall as if it had been crucified and another hanging by its collar and then shot with an air gun.
Other animals are seen dead – including one which the girls apparently cut open to pull out its internal organs.
Outraged social media users alerted police after the graphic images were posed online and local residents started a petition calling on the authorities to act.
Both girls are students and live in the city of Khabarovsk in south-eastern Russia’s Khabarovsk Krai region.
They allegedly adopted unwanted animals, promising to look after them but instead tortured and killed them, posting photographic evidence online.
In one image, Orlova is seen clutching a cute puppy with her mouth open wide as if she is about to bite it.
Another picture shows Kristina menacingly holding a hammer and a nail.
Ear Hustle 411 will Not show the images but if you like to see the images go here where a Petition is going on to lock them up forever.