UPDATE 10pm: Police in Rotterdam stopped a van with Spanish licence plates containing a number of gas bottles close to the venue of a concert by an American rock band that was cancelled following a threat, the mayor of the Dutch port city said.
Mayor Ahmed Aboutaleb said at a hastily arranged press conference that the van's driver had been detained and was being questioned.
Allah-Las are a four-piece band from Los Angeles.
In an interview with The Guardian last year, band members said they chose the word Allah, Arabic for God, because they were seeking a "holy sounding" name.
They said they did not realise it might offend Muslims.
Lead singer Miles Michaud told the newspaper the group received emails from Muslims around the world who said they were offended.
Michaud said the band usually wrote back and explained its intentions were honourable "and mainly they understand".
EARLIER: A concert in the Dutch port city of Rotterdam by American rock group Allah-Las was cancelled on Wednesday night because of a "terror threat", police said in a statement.
The mayor of Rotterdam said the driver of a van from Spain had been detained after a warning from police in that country which itself suffered weekend terror attacks in Barcelona and Cambrils.
"Police took this information seriously enough that after discussion with organisers it was decided to cancel the event," a Rotterdam police statement said.
An investigation was under way, but no arrests have been made, police said.
Concert organiser Rotown said earlier on Twitter that the concert venue, a former grain silo called Maassilo, was being evacuated because of the unspecified threat and concertgoers would get their money back.
The show had not yet started when the decision to cancel it was made.
Dutch television showed officers in body armour outside Maassilo and what appeared to be members of the band leaving the venue in a white van with a police escort.
The band did not immediately respond to emails seeking comment.
Allah-Las is a four-piece band from Los Angeles.
In an interview with British newspaper The Guardian last year, band members said they chose the word All, Arabic for God, because they were seeking a "holy sounding" name and did not realise it might cause offence.
"We get emails from Muslims, here in the US and around the world, saying they're offended, but that absolutely wasn't our intention," lead singer Miles Michaud told the newspaper.
"We email back and explain why we chose the name, and mainly they understand."
[timgcap=Rotterdam (file pic)]rotterdamSkyline_large.jpg[/timg]
The mayor, Ahmed Aboutaleb, said police stopped a van with Spanish licence plates containing a number of gas bottles close to the venue.
He said the van's driver was being questioned.