Law enforcement agencies conducted a raid targeting outdoor marijuana gardens at homes in the Roseland area in southwest Santa Rosa and unincorporated Sonoma County Wednesday morning, a sheriff's lieutenant said.

The raid was carried out at 32 homes in a four-block area near Moorland and Bellevue avenues beginning at 8:45 a.m., Lt. Dennis O'Leary said.

The marijuana plants were growing in backyards that were between 100 and 400 square feet, O'Leary said. Each garden contained between 30 and 40 plants.

Details on the number of arrests were not available Wednesday afternoon, but most of the homes were occupied, O'Leary said.

Approximately 140 law enforcement officers from the sheriff's office, Santa Rosa Police Department, the California Highway Patrol, the FBI's Safe Streets Task Force, and the Department of Homeland Security participated in the raid, O'Leary said.