Police say more than two dozen people have been arrested after a nine-month investigation into biker gang activity in the Niagara area.

More than 220 officers — including some from the Hamilton, Toronto and Guelph police forces — took part in early morning raids Wednesday, executing about 30 search and arrest warrants in and around the Niagara area.

Niagara regional police say they began investigating the activities of the Outlaws motorcycle gang and Black Pistons motorcycle gang in the area earlier this year.

The investigation — dubbed Project Resurgence — was expanded in April to include investigators with Canada Border Services Agency, Ontario Provincial Police and RCMP.

Police say they uncovered evidence of narcotics trafficking — including heroin, cocaine and marijuana — along with evidence of weapons trafficking, break and enter, assault, extortion and participation in a criminal organization.

The 28 Niagara residents arrested face charges including narcotics offences, conspiracy, break and enter and criminal organization-related offences.

Niagara police say the investigation is ongoing and more charges and arrests are expected.

They plan to hold a news conference Thursday to display some of the items seized.