Authorities hunting one suspect after possible terrorist attack in Utrecht; Residents told to stay inside

The Dutch authorities are looking for one suspect following a possible terrorist attack in Utrecht on Monday morning, Pieter-Jaap Aalbersberg, head of the national coordinator for counterterrorism and security NCTV, said in a press conference on Monday afternoon. He added that it can not be ruled out that more people were involved.

The authorities' top priority at this stage is finding the suspect at large. Aalbersberg called on citizens to listen to what authorities say and give them room to perform their duties. Utrecht municipality is telling everyone in the city to stay indoors while the search for the suspect is ongoing.

A man opened fire in a tram on 24 Oktoberplein in Utrecht at around 10:45 a.m. on Monday. Multiple people were hurt. Witnesses report that one person was killed, but this has not been confirmed by the authorities.

The terrorism threat level for the province of Utrecht was increased to the highest level 5 until at least 6:00 p.m. on Monday. "A terrorist crime can not be ruled out. Therefore the threat level for the province of Utrecht was increased to 5. In the rest of the country it is still 4", Aalbersberg said. "For the time being there is no further reason to see more threat in the rest of the country. That is why the level in the rest of the country remains at level 4."

A level 5 threat level means that there is a critical terrorism threat in the Netherlands. The threat level is increased to 5 if the NCTV has concrete indications that terrorists are about to commit an attack in the Netherlands, if there was a terrorist attack in the Netherlands, and if there is a chance of another attack. Level 4 means that there is real chance of an attack, but that the authorities have no concrete indications that one is being planned.

With the increased threat level, several institutions and organizations shut their doors in Utrecht on Monday. The university there is asking students to stay indoors and telling employees not to leave until authorities deem it safe to do so. The Hogeschool Utrecht also locked entrances, telling students not to visit the campus while the extra security is necessary.

All mosques in the city were reportedly closed.

The Ulu Mosque closed after close consultation with police, a spokesperson for the religious center told De Telegraaf.

Meanwhile, security was increased at sites across The Netherlands, even as NCTV kept the threat level at 4 countrywide. More security was seen at Schiphol, the broadcast center in Hilversum, and Parliament.