Officials confirmed Tuesday that Mateusz W., a student at the Catholic University of Lublin, was arrested in November at his apartment in eastern Poland.
Authorities allege he was planning a mass-casualty attack at a Christmas market in an unspecified Polish city and was seeking contact with the Islamic State.
Poland’s special services spokesperson Jacek Dobrzyński said the suspect had taken concrete steps toward carrying out an attack and supporting a terrorist organization. Prosecutors charged Mateusz W. with “undertaking preparatory actions to carry out a terrorist attack that could have resulted in the death or serious injury of many people.”
According to the prosecutor’s office, the suspect also attempted to establish contact with a terrorist group in order to obtain assistance in executing the planned attack.
“The aim of the crime was to intimidate many people and support the Islamic State,” Dobrzyński said in a post on X. “During the investigation, Internal Security Agency officers seized data carriers and items related to Islam.”
Speaking at a press conference, Dobrzyński said the suspect was “very fascinated by Islam,” had sought links to the Islamic State, and was actively preparing an attack during the Christmas market season. Authorities declined to identify the specific city involved, citing concerns about public panic.
The suspect has been placed in pretrial detention for an initial period of three months. Officials did not release further details about how advanced the alleged plot was or what type of explosives were being considered.
The case comes amid heightened security concerns across Europe during the holiday season. Dobrzyński referenced a separate incident earlier this year in which Polish authorities charged three 19-year-old men accused of stockpiling pyrotechnic materials and planning terrorist attacks, including a suspected plot targeting a school in the northern city of Olsztyn.
“You are familiar with the issue from Olsztyn,” Dobrzyński said. “Now we have another example of preparing an attack before Christmas.”
He also pointed to recent and past terror attacks carried out during the holiday season across Europe and abroad, urging continued vigilance.
The plot follows the recent mass shooting at Bondi Beach in Australia, where suspects reportedly linked to ISIS opened fire during a public gathering, killing at least 15 people. European security services have repeatedly warned that Christmas markets remain symbolic and attractive targets for extremist violence.
