Police have arrested a 22-year-old man in the southern Dutch province of Brabant, hours after a rock concert was cancelled because of an alert from Spanish police.
The man was detained in the early hours of Thursday as part of the inquiry into the terror threat, said police.
The alarm on Wednesday centred on a gig involving US band the Allah-Las, due to perform in Rotterdam’s Maassilo.
A Spanish van driver was detained close by but police said he was not involved. The reported tip-off from Spanish police came less than a week after the jihadist attacks in Barcelona and Cambrils in which 15 people died.
Police wearing bulletproof vests were sent to the venue, which was evacuated.
A van with a Spanish number plate was stopped while driving erratically in a nearby street and a bomb squad was sent to examine the vehicle. Gas canisters were found inside and the driver was detained, but within hours Dutch authorities were playing down any potential link.
The man was later described by police as drunk. The Spanish driver was said to be a mechanic who had the gas canisters in his vehicle as part of his job. “He didn’t have anything to do with the threat to the venue,” Rotterdam police spokesman Gijs van Nimwegen said.
Hours later, at 02:00 (00:00 GMT), a special police unit raided a house in Brabant. In a statement (in Dutch), police said a man had been arrested and his home searched. No details were given of where in Brabant the raid took place or who the suspect was.
The Dutch DSI counter-terrorism unit is involved in the investigation and a police spokesman told local TV in Brabant that the inquiry was “in full swing”. The Netherlands’ National Co-ordinator for Security and Counterterrorism, Dick Schoof, said the Brabant arrest had no link to the Spanish driver.
Mr Van Nimwegen said the tip-off from the Spanish authorities “wasn’t about a fire or something, it was a possible terror threat; we weren’t going to take any chances”. The terror threat in the Netherlands has remained at the second highest level of “substantial” since 2013, with authorities saying the chance of an attack is real.
The Allah-Las have often received threats because of their name and the Spanish warning led to the gig being called off at the last minute. The Los Angeles-based indie-rock band were due to play in Warsaw later on Thursday and Polish media said the concert was expected to go ahead as planned.
In an interview last year, the Allah-Las told The Guardian newspaper that they regularly received messages from Muslims offended by the use of the word Allah – Arabic for God – in the group’s name. They said they had wanted a religious-sounding name after being inspired by the group The Jesus and Mary Chain.