Dutch police on Tuesday questioned the Turkish-born suspect in a deadly shooting on a tram in the city of Utrecht and two other people arrested in connection with the rampage.
Gokmen Tanis, 37, was arrested after a massive eight-hour manhunt on Monday following the shooting in which three people were killed and five others injured.
The motive remains unknown, with Dutch officials saying they are still investigating a possible terrorist link but cannot exclude that it may have been a family dispute.
Utrecht police said late on Monday that they had arrested two other men in connection with the attack but gave no further details about them.
"As for the three suspects detained in connection with the shooting incident in 24 Oktoberplein, Utrecht, these three people are still being held and are still suspicious," Utrecht police said on Twitter on Tuesday.
The police statement came after the mayor of Utrecht told Dutch radio the two other men had been freed.
Mourners began to lay flowers on Tuesday at the site of the attack near the 24 Oktoberplein square in memory of the victims, who have not yet been formally identified.
Flags were flying half-mast on many buildings around the country.
Public transport was running again after forensic police finished their investigations at the scene and removed the tram on which the shooting erupted.
Dutch Prime Minister Mark Rutte was chairing a cabinet meeting on the attack, which has raised security fears a day before provincial elections in the Netherlands.
- Family dispute? -
Turkish President Recep Tayyip Erdogan said his country's intelligence agency was "looking into the matter" and raised the possibility that it was a family dispute.
"Some say it is a family matter, some say it is a terror attack ... Our intelligence agency is looking into the matter. I haven't talked to our intelligence chief yet", Erdogan told Ulke TV.
Dutch media have reported that the suspect had a long criminal background and was only released from jail two weeks ago on a number of charges.
Broadcaster NOS reported that some members of his families had links to fundamentalist Islamic groups, but also that he was known for unstable behaviour after divorcing his wife two years ago.
Police and witnesses say gunfire broke out on the tram on Monday morning, sending people fleeing and triggering a huge police response.
Mosques and schools were closed across the Netherlands' fourth-largest city following the bloodshed, before heavily armed officers surrounded a building and arrested Tanis.
Support for the Netherlands poured in from around the world including the United States, the EU and Russia after the attack.
US Secretary of State Mike Pompeo said "America stands with you. We will continue to do all we can to help you in this terrible time of tragedy."