The arrests give justification to fears that the Scandinavian gang war between biker gangs Hells Angels and Bandidos could spread to Germany in the wake of police pressure, the closure of some clubs – and crucially, some members switching between gangs.

A tip from Sweden led to the arrests in the northern port town of Rostock of a Swede, a Macedonian and an Iranian – the latter two of whom live in Denmark.

Two men are alleged to be Bandido members while the third was said to be in close contact with the gang.

Arriving in a rented car from Denmark on the ferry, the three men had almost a kilogramme of explosives, a detonator and bullet-proof vests. The men are still in custody, the Tagesspiegel newspaper said.

Authorities in Berlin are keeping the men they think would have been targets of the attack under observation.

Police sources told the paper this would probably include the former head of the Berlin Bandidos chapter who switched to the Hells Angels in May in order to avoid an official ban.

Those who know the scene say that switching loyalties is punishable and that the Bandidos have lost influence within Berlin to the Hells Angels and could thus be launching attacks to win back territory.

Violence between the gangs has escalated in Germany over the last few months, while the Hells Angels issued what amounted to a declaration of war at the start of July, saying no other gang would be tolerated in Berlin.

The Local Germany