THE HAGUE, Netherlands (AP) — Rotterdam police are continuing to question a man who was arrested on suspicion of involvement in a threat that triggered the cancellation of a concert by American rock band Allah-Las.

The 22-year-old man was arrested early Thursday on suspicion of involvement in planning a terrorist attack. The Dutch justice minister later said the man was suspected of spreading a threat on the internet.

Police spokeswoman Mirjam Boers said Friday the nature of the man's involvement in Wednesday's threat is still being investigated.

A Spanish man detained Wednesday night while driving a van containing gas canisters near the concert venue was released Thursday after investigations uncovered no link to the threat.

Authorities ordered the Allah-Las concert canceled Wednesday night after receiving "concrete" warnings from Spanish police.