IRON RIVER — Four people were arrested Wednesday in Iron River after a month-long investigation, law enforcement officials said.

Authorities did a warranted search of a residence at 310 Blossom Ave. after detectives learned the occupants had narcotics and a loaded pistol, according to a news release from Det. Lt. Tim Sholander of the Upper Peninsula Substance Enforcement Team, or UPSET.

The residence was in proximity of West Iron County High School, which was temporarily placed on lockdown until the suspects were taken into custody.

Detectives reportedly found various prescription pills, evidence of drug distribution and two firearms while searching the home.

Two suspects were arrested on charges related to the distribution of cocaine and other drugs, Sholander stated, while the other two were arrested for probation violations.

All four suspects are in the Iron County Jail. Names are being withheld pending arraignment.

The investigation is still ongoing. No other information is being released at this time.

UPSET was assisted by the Iron River Police Department, Caspian Police Department, Iron County Sheriff’s Department and the Michigan State Police.