Dutch police arrested a suspect for a shooting attack on a tram in the city of Utrecht on Monday, which killed three people and wounded nine people.
Police earlier said Turkish-born Gokmen Tanis, 37, was responsible for the attack on the morning tram at 24 Oktoberplein, a tram station to the west of Utrecht.
As reported in the press conference: The police arrested a man for his involvement in the shooting at the #24oktoberplein in #Utrecht.
— Politie Utrecht (@PolitieUtrecht) March 18, 2019
Heavily armed counter-terrorism officers surrounded a building where the gunman was believed to be hiding.
Dutch counter-terrorism authorities said shots were heard at several locations on Monday afternoon local time after the tram shooting.
Police ordered locals to stay indoors and mosques were told to temporarily close after reports of gunfire near a Utrecht masjid.
The terror alert level was raised to its highest ever for the area around Utrecht.
Police tweeted a security camera image of Mr Tanis and emerging details pointed to his links to extremists.
A Turkish businessman living in Utrecht told BBC Turkish that Tanis had connections to ISIS and had fought in Chechnya.
Utrecht police have not ruled out the possibility of more than one suspect connected to the tram shooting but said all efforts were channelled towards catching Tanis.
"We cannot exclude a terrorist motive," said the Dutch anti-terrorism co-ordinator Pieter-Jaap Aalbersberg.
"A lot is still unclear at this point and local authorities are working hard to establish all the facts," Mr Aalbersberg said.
One witness said he heard several shots fired and saw a woman lying on the ground, Dutch broadcaster RTV Utrecht reported.
“I came from my job when it happened," Jimmy de Koster said. "I was standing at the traffic lights on 24 Oktoberplein and I saw a woman lying down.
"I think she was between 20 and 35 years old. At that time I heard bang, bang, bang – three times.
“Four men walked very fast towards her and they tried to drag her away, and then I heard bang, bang, bang again and those guys let go of that woman."
Prime Minister Mark Rutte held an emergency Cabinet meeting and said "a terror motive” was being investigated.
Mr Rutte said a feeling of disbelief and disgust swept the nation after the attack.
Dutch radio said security had been increased in the Hague and across government buildings.
Politicians suspended campaigning for the Dutch Senate elections set to be held on Thursday.
Geert Wilders, leader of the main opposition right-wing Freedom Party, tweeted that "the news from Utrecht is terrible".
Utrecht, the fourth largest city in the Netherlands, is a university town, popular with international students and with a small resident population of about 350,000.
The city is considered the centre of Dutch industry and religion, with the headquarters of the Netherlands’ Catholic and Protestant churches.
The shootings follow days after a massacre at two mosques in Christchurch, New Zealand, where 50 people were killed.
New Zealand Prime Minister Jacinda Ardern pledged to ban semi-automatic weapons 24 hours after the attack.
Australian Brenton Tarrant, 28, a self-described white supremacist, has been charged with murder.
