More than 180 foreign nationals are being questioned by authorities in WA following a major multi-agency operation targeting organised crime.

A series of pre-dawn raids were carried out on Saturday and were focused on properties in Perth’s north.

WA Police, Australian Federal Police and also the Australian Customs and Border Protection Service were involved in the searches.

“The search warrants form part of a complex investigation focused on money laundering and other illegal activities,” according to a WA Police statement.

“As a result of the search warrants more than 180 foreign nationals are currently being questioned.

“WA Police is working with the Department of Immigration and Border Protection to identify suspected illegal workers.”

Cash, firearms and computers were also seized during the raids, and property searches are ongoing.

A significant police presence remains in the Carabooda area.

The operation was described as a joint operation involving agencies attached to Project Tricord and Operation Polo, and there were raids also in Victoria.

Police said the raids were part of “ongoing efforts to identify, target and dismantle organised crime syndicates operating in Western Australia”.