Police in New Zealand made dawn raids on biker gangs on Friday, seizing drugs, explosives and weapons including pipe bombs.
More than 30 properties were raided in the North Island city of Auckland and across the South Island.
Properties searched included the headquarters of the Hell's Angels.
Twenty-eight people were arrested and charged with a range of offences.
Superintendent Gary Knowles says the operation took 18 months to plan.
He called it a huge blow to Hell's Angels plans to expand operations in New Zealand.
He says the discovery of pipe bombs suggests the group was willing to main or kill members of the public.