Police say nearly 30 people have been arrested and drugs and guns seized in a multi-agency investigation of what's described as a drug trafficking organization that operated in Oregon and Washington.

Pendleton, Ore., Police Chief Stuart Roberts says more than 100 law enforcement officers from federal, state and local agencies fanned out Thursday in northeast Oregon and southeast Washington to serve search warrants on homes, vehicles and a storage locker. The operation also sought to arrest those with outstanding warrants related to the yearlong investigation.

Roberts says the investigation aims to dismantle an organization that has been operating in Umatilla, Morrow and Union counties, as well as southeast Washington and southern Oregon.

Among the items seized were 6 1/2 pounds of methamphetamine, nearly 800 prescription pills and 23 pounds of processed marijuana, as well as 21 guns.