A man suspected of killing three people in a shooting aboard a tram in the city of Utrecht this week admitted his guilt to a judge on Friday and has said he acted alone, Dutch prosecutors said.

Turkish-born Gokmen Tanis, 37, is accused of carrying out the March 18 shooting with terrorist intent. Authorities are also investigating whether he had other personal motives. Prosecutors gave no further details of Tanis’ confession, citing the importance of further investigation.

The detention of Tanis, who was arrested after a seven-hour manhunt on Monday by Dutch security forces, was extended on Friday by the maximum amount allowed of two weeks.

He is due to appear before court again within two weeks, at which point his detention can be extended by up to 90 days.

A 40-year old man, who was held on Tuesday because Tanis was arrested in his house, was released on Friday as there was no evidence of his involvement in the shooting in any way, the prosecutors said.