Four individuals were detained at Bilbao airport in northern Spain on Tuesday following clashes that erupted as activists returned from a Gaza-bound flotilla. The six campaigners arrived on a flight from Turkey after being held by Israeli authorities, according to officials.

Supporters had gathered in the arrivals hall to greet the activists when tensions escalated. A relative attempting to approach the campaigners was reportedly blocked forcefully by a police officer, sparking a confrontation between the groups. Video footage broadcast by a public station showed police officers using batons and restraining passengers on the ground amidst jeers from bystanders.

The Basque regional police force, known as the Ertzaintza, confirmed the arrests, citing charges of serious disobedience, resisting arrest, and assaulting law enforcement officers. The police also announced that their internal affairs division has initiated an investigation to assess whether the officers’ actions at the airport complied with established procedures.