Police raided multiple Oakland locations this morning in an attempt to dismantle a large heroin trafficking ring, according to authorities.

The raids, conducted by agencies including Oakland and San Francisco police, the Drug Enforcement Agency and the Federal Bureau of Investigation, began early this morning, and Oakland police will hold a 3 p.m. news conference to discuss the effort, according to authorities.

The raid comes on the heels of San Francisco police busting 103 drug dealers in The City in a six-day period. Many of those dealers came from the East Bay to sell their drugs, predominantly crack cocaine.