A 19-year-old Luxembourg man faces multiple charges after a violent assault in Mamer, where masked attackers allegedly stripped, bound, and robbed another teenager in a car park, authorities confirmed Friday.

Luxembourg authorities have launched a judicial investigation following a violent altercation in a Mamer car park on the evening of 26 May. The public prosecutor's office confirmed the inquiry on Friday, naming a 19-year-old Luxembourg national and several unidentified suspects.

According to the prosecutor's statement, police were despatched to the scene near a wastewater treatment plant after a second 19-year-old man reported being assaulted. The victim alleged that 12 masked individuals attacked him, forced him to undress, and threatened to kill him. The assailants also bound him with zip ties, pulled his hair, and stole his mobile phone and car.

The incident occurred after the victim arranged to meet the 13-year-old sister of one of the alleged attackers at the car park, following contact via social media.

Luxembourg police, including the anti-terror unit of the criminal police, identified both the girl and her brother. The brother was brought before an examining magistrate on Thursday and faces charges of assault, verbal abuse, violent theft, and making threats of violence.

Three additional minors have since turned themselves in to authorities. The investigation remains ongoing.

The public prosecutor's office emphasised that all suspects benefit from the presumption of innocence.