Dutch police have arrested a second suspect in relation to a potential terror attack which forced the cancellation of a concert in Rotterdam.

Armed officers swooped on the Maassilo concert venue around 7pm to find a van with Spanish licence plates filled with gas canisters outside, following a tip-off from Spanish police.

The driver of the vehicle was arrested, though Rotterdam mayor Ahmed Aboutaleb said it was not clear whether the threat and the van were connected.

The second man, 22, was arrested during police raids in the southern province of Brabant early on Thursday and was being questioned about the Rotterdam threat, the police said.

Anti-terror police canceled a gig by American rock band Allah-Las in Rotterdam on Wednesday night before a Spanish van filled with gas canisters was found outside

A bomb squad was brought in to search the vehicle containing the gas canisters after it was found several streets away from the venue

Security appeared to taking a cautious approach after 22 were killed and more than 100 injured when a suicide bomber blew himself up at an Ariana Grande concert in Manchester in May.

And less than a week ago, terrorists in Spain killed 15 in two vehicle attacks after an attempt to create bombs using gas canisters failed.

Police said the man in Brabant was arrested after a search of his home, saying: 'He is in custody and being questioned about the threat in Rotterdam.'

Rotterdam Mayor Ahmed Aboutaleb said it was not clear whether the tip-off and the detection of the van were connected.

He warned against 'swift conclusions' while noting the white van had Spanish licence plates and had been flagged for circling near the concert venue.

The concert was cancelled at around 7pm, shortly before doors were to be opened for guests.

A judicial source in Spain said the alert given to Dutch authorities is not directly connected to the attacks in and around Barcelona last week.

The source said the tip resulted from an investigation that has been under way for some time and had no direct relation to the two vehicle attacks in Catalonia.

Spanish authorities said the tip came after a long-running investigation, and had no direct link to last week's terror attack that killed 15

The driver, who is Spanish, was arrested and is being questioned, though Amsterdam's mayor said it is not clear if the alert and the van were linked

The driver of the van has been arrested and is being questioned by police, Rotterdam mayor Ahmed Aboutalebsaid has said

EOD'ers onderzoeken op Mijnsheerenlaan verdachte auto met Spaans kenteken. #terreurdreiging pic.twitter.com/Y3cD7p38Ae — robert bas (@robertpbas) August 23, 2017

The venue was cordoned off as a bomb squad was brought in to search the van.

A video from the scene shows several officers inside the back of the vehicle examining objects with flashlights.

It is not clear why the venue was targeted, but California band Allah-Las were due to play that evening. Their name has caused offense to Muslims in the past.

A venue owner Turkey once called off a gig because he did not feel comfortable with the moniker which uses the Arabic word for God.

In an interview with The Guardian last year, the band said they chose the name simply because they wanted something 'holy sounding' and did not realise it would provoke such a strong reaction.

'We get emails from Muslims, here in the US and around the world, saying they're offended, but that absolutely wasn't our intention,' singer Miles Michaud said.

Images from outside the venue show officers surrounding the concert hall which has been taped off, as bemused members of the public leave the scene.

Armed officers swooped on the gig after a tip-off from Spanish colleagues over a potential terror attack almost a week after the Barcelona atrocity

Allah-Lah were evacuated from the back of the venue and taken away under police guard

It is not clear why the gig was targeted, though the Allah-Las say their name has caused offense to Muslims in the past

Allah-Las were escorted from the venue after the gig was called off, and guarded by officers on motorbikes as they drove away in van, it is reported.

The band said in a statement: 'In response to the police, we are forced to cancel the concert of Allah-Las tonight in the Maassilo.

'It does not make sense to come to the Maassilo. Sorry for the inconvenience, more information follows.'

The building has a total capacity of around 1,000 people. Allah-Las were supposed to share the bill with Dutch-Turkish group Altin Gün.

Thirteen people were crushed to death and more than 100 injured when terrorist Younes Abouyaquob drove a van down Las Ramblas in Barcelona last Thursday.

Abouyaaquob then stabbed another man to death as he stole his car and fled the scene, while a second attack by five more jihadis killed one woman and wounded another 16 people in the town of Cambrils.

Maassilo was put on lockdown after the van was found a short distance away

Rotterdam Mayor Ahmed Aboutaleb spoke to journalists on Wednesday night after the discovery of the van

Police wearing bullet-proof vests surrounded the venue as bemused concert-goers were led away on Wednesday night

A bomb squad was brought in to search the van as concert-goers were sent away and the venue cordoned off

The band's singer Miles Michaud (pictured) said he chose the name because he wanted something 'holy sounding' and did not realise it would cause offence

All five Cambrils attackers were shot dead by police at the scene, while Abouyaaquob was shot dead in Subirats on Monday. Four more suspects were arrested and appeared in court on Tuesday.

In court documents, a judge said the dead men launched their attack after a bomb factory filled with gas canisters in the town of Alcanar exploded, killed the alleged plot mastermind and his assistant.

Police video released the same day showed officers searching the homes of the arrested suspects, where more gas canisters were found.

A chilling message posted by a pro-ISIS account later the same day warned of further attacks by terror cells still embedded inside Europe.