A court in Sosnowiec, southern Poland, ordered one of the teenagers to be placed in a juvenile detention centre for three months, while the other was taken to a police juvenile detention facility, according to a statement.
The ABW said it was investigating how the teenagers became radicalised, reconstructing their network of contacts and checking whether other people may have influenced them.
On September 13, ABW officers, assisted by police, detained a 16-year-old identified only as Kacper K. under Polish privacy laws.
The agency said its earlier findings indicated that he had been active in numerous groups on the Telegram and Discord digital platforms and had maintained contacts with people linked to extremist circles.
"An initial analysis of the devices and data secured during the operation revealed neo-Nazi, racist and antisemitic material," the ABW said.
It added that the material also included content concerning terrorist attacks, mass killings and so-called lone shooters.
Further analysis led investigators to identify another person who operated in the same online environment and maintained contact with Kacper K., the agency said.
On September 16, ABW officers, assisted by police officers, detained a second 16-year-old, identified as Wiktor Ś.
The agency said he had been active in the same online communities and had maintained contact with Kacper K.
He had also offered to sell Kacper K. items bearing Nazi German symbols, which were seized by investigators, the ABW said.
The Sosnowiec District Court ordered Kacper K. to spend three months in a juvenile detention centre. Wiktor Ś. was placed in a police juvenile detention facility.
The ABW said investigators were analysing the seized devices and online communications as they try to trace the teenagers' network of contacts.
The investigation is intended to establish how the radicalisation process developed and whether other people were involved, the agency said.
"Radicalisation does not begin with an attack. It starts much earlier—with content, contacts and an environment that can lead to a real threat," the ABW said in its statement, adding that its role was to identify such processes before they turn into action.
(gs)
Source: IAR/PAP