Atlanta police discovered a marijuana grow operation with plants worth more than half a million dollars in southwest Atlanta on Monday.

At least 250 plants were found in a home in the 3200 block of Telford Terrace, police said.

Authorities, who had received several tips about the home recently, were in the area Sunday responding to an unrelated medical call when they noticed the odor of marijuana coming from the home, Atlanta police spokesman Officer John Chafee said.

Investigators went to the home and tried to contact the residents, but no one answered the door, he said. A K-9 was brought to the area and indicated from the roadway that drugs were in the house.

A search warrant was obtained and was served around noon Monday, Chafee said.

Four rooms of the home — two upstairs and two in the basement — contained marijuana plants, he said. There was also an irrigation system set up to provide water for the plants, and cut plants were hanging in the hallway to dry.

The officer said people were living at the home as well but have not been located.

“We are in the process of obtaining arrest warrants for the suspects,” he said. “No arrests have been made at this time.”

Police were on the scene loading the plants into a white van Monday night.