Dutch officials found a van with Spanish licence plates loaded with gas canisters late Wednesday, after cancelling a rock concert in Rotterdam following a terror attack warning.
The Spanish driver of the van "was arrested and taken to the police station," Rotterdam police said in a Tweet.
Dutch bomb squad officials "were investigating the van," they added, which had been found close to the Maassilo concert hall in the city.
It comes less than a week after twin car-bomb attacks in Spain killed 15 people on Thursday. Those attacks were claimed by the Islamic State group.
Earlier in the evening the Dutch authorities had decided to cancel the concert by American rock group Allah-Las in Europe's largest port city after receiving a tip-off from Spanish police around 5:30pm (1530 GMT) about a possible terror attack.
The Maassilo venue in Rotterdam announced that "due to a terrorist threat, the Allah-Las concert will not take place this evening, on police orders".
Rotterdam police confirmed the decision was taken due to a "possible terrorist threat" and that the van's driver had been arrested.
The city's mayor, Ahmed Aboutaleb, told a hastily-called press conference that an investigation would be launched to determine if the van was linked to the reported terror threat. He added it was important not to jump to any hasty conclusions.
The building where the concert was to be held, which can hold about 1,000 people, was evacuated and was searched by the Dutch anti-terror squad.
The Dutch national broadcaster NOS showed images of police officers, wearing bullet-proof vests combing in the area.
The Netherlands has so far been spared from the slew of terror attacks which have rocked its closest European neighbours in past years.
But amid a number of scares here in recent months, and reports that people linked to some of the attacks may have crossed briefly into the country, concerned top Dutch security and intelligence officials have been keeping a wary eye on events.
"The threat level to the Netherlands is substantial which means that an attack in the Netherlands is a real danger and can actually happen," national counter-terrorism coordinator Dick Schoof warned in May 2016.
Schiphol airport, outside Amsterdam, is one of Europe's busiest air hubs. It was the scene of a late-night evacuation in April 2016 when a drunken, homeless man sparked a security scare, just a few weeks after the Brussels metro and airport suicide bombings.
And in November, Rotterdam airport was the target of a reported terror threat, which also turned out to be false.