RAMONA, Calif. - Three men arrested in connection with a marijuana growing operation in a Ramona residence were jailed Saturday.

The arrests were made after sheriff's detectives, backed by a SWAT unit, served a search warrant at a home in the 300 block of Fergalhi Road following a month-long investigation, said Sgt. B. Hout of the San Diego County Sheriff's Department.

Inside the residence, detectives found 120 marijuana plants, five pounds of high-grade marijuana with an estimated street value of $15,000, a firearm and $17,800 in cash, Hout said.

Arrested on suspicion of marijuana cultivation, possession of marijuana for sale and possession of a dangerous weapon were Joshua Day, 27, Justin Lambert, 34, and Douglas Politte, 27, Hout said.

The suspects had installed a steel security screen and steel gates at the residence, where they also kept an aggressive dog, he said.