Clusters of tents form makeshift living space along Southampton Street in the "Mass. and Cass" area on Sunday, Sept. 26, 2021, directly across from the Boston Fire Department administrative headquarters. Photo by Sam Doran | State House News Service

Officials in Boston are beginning to clear a sprawling homeless camp, citing a crisis of opioid addiction there.

Notices posted on Sunday near the intersection of Massachusetts Avenue and Melnea Cass Boulevard, an area commonly known as Mass and Cass, say officials will start a “general cleanup of this public space” starting at 7 a.m. Monday.

Last week, acting Mayor Kim Janey declared addiction and homelessness a public health emergency and said the roughly 150 tents that have been set up in the area, mostly along Theodore Glynn Way, will be removed.

The order also says police will continue to enforce all laws related to drug trafficking, human trafficking, disorderly conduct and trespassing.

“Tents are not appropriate for housing, they lack clean water and adequate facilities,” Janey said at the time. “We cannot let our most vulnerable residents continue to suffer in these encampments.”

It’s not clear where the city plans to relocate people displaced by the removal of the encampment.

City officials said those dependent on opioids will be connected with treatment and permanent shelter options. They stressed that the city is not criminalizing homelessness, and no one will be forcibly removed.

The area, home to numerous methadone clinics and social services, has long been a haven for crime and illegal drug sales and use, often in the open.