As reported by Censor.NET, they state that they joined the terrorists in order to make extra money. They had been promised a salary of 15,000 rubles ($234). They had been selected to a group by a Russian citizen call sing Shaman. Shaman was accompanied by an adviser, a Russian career officer.
The unit of service of the detainees is commanded by Russian citizen 'Lekha Pitersky' - a major of the Russian police with combat experience in Chechnya. As ordered by their Russian curators, the militants were scouting for personnel, equipment, and redeployment of the Ukrainian Armed Forces' units near Leninske village with the purpose of subsequent provocations against the Ukrainian army. They also attempted mining an area near Shyrokyne, Mariupol district.
Related materials: Russian aggression against Ukraine