On the morning of 14 December 2023, Danish police officers arrested three people in Denmark on suspicion of plotting a terrorist attack, while another person was arrested in the Netherlands. The arrests were made during coordinated operations across the two countries. According to Dutch police, the suspect arrested in Rotterdam was linked to an ongoing terrorism investigation, while the three suspects arrested in Denmark were suspected of planning to carry out an act of terror. A senior official for Denmark’s Security and Intelligence Service (PET) stated that the threat was related to criminal gangs, referring to the outlawed Loyal to Familia gang. The arrests come two days after the Dutch government raised the countrywide terror threat alert to Level 4 — the second-highest warning on a five-tier scale — indicating that the risk of an attack in the Netherlands is “substantial.”