People lay flowers during a silent march in Utrecht in honour of the people wounded or killed in an attack on a tram on Monday, in Utrecht, Netherlands March 22, 2019. REUTERS/Piroschka Van De Wouw

AMSTERDAM (Reuters) - A Dutch judge on Thursday extended for three months the detention of the suspect in a shooting that killed four people in the city of Utrecht last month.

Turkish-born Gokmen Tanis, 37, is accused of carrying out the shooting aboard a tram out of terrorist intent. Authorities are also investigating whether he had other personal motives.