PORTLAND, Ore. -- A drug-related search warrant was served in a southwest Portland apartment complex near Wilson High School for the second time in a month.

Police found a large-scale marijuana growing operation inside the apartment on SW 18th Drive early Tuesday.

Photo courtesy: Portland Police Bureau

Police found plants and harvest pot in an apartment near a southwest high school.

Two people were arrested after investigators received a tip about the operation during the first drug raid, in which two people were arrested for selling drugs to Wilson High School students.

 More: Wilson High neighbors selling pot to students

Police found 31 marijuana plants and three pounds of harvested pot in this raid.

They arrested Monte Simpson and Jennifer Joyner, both 31, and charged them with manufacturing controlled substances within 1,000 feet of a school and marijuana possession.

There is no evidence that the two investigations are connected or that the suspects were dealing to area high school students, police said.