After an alleged assault on a correctional officer, Boston police swept the area around Melnea Cass Boulevard and Massachusetts Avenue last week, arresting dozens and telling homeless people to relocate.

Police were seen destroying wheelchairs during the action, which authorities are calling "Operation Clean Sweep."

City Councilor Michelle Wu described the move as "cruel."

Boston Mayor Marty Walsh stood by the action, and told Boston Public Radio on Friday the sweep highlights a tightrope the city is walking to provide vital resources to addicts and maintain public safety.

"Certainly, I don't want to arrest people who are sick and suffering, but we have to make sure these drug dealers that are preying on these people, send a message to them, don't come to this area," he said. "We want to try and get as many people into treatment."

The site of the sweep is near Boston Medical Center, which is the biggest provider of free care in the state, said Walsh. The area has historically been a hub for people seeking drug treatment.

"In this particular area of the city of Boston at Melnea and Mass Ave, there's a lot of recovery programs, a lot of good work happening, as long as I remember, this area always had people who are sick and suffering in that area," he said.

Walsh said police arrested people with outstanding warrants who were dealing drugs and who had committed assault and battery.

"I don't think anyone got arrested for being a heroin addict," he said.

Suffolk County District Attorney Rachael Rollins has also critized the sweep.

"Public safety begins with public health. As I've long made clear, we cannot arrest our way out of a health and resource crisis. People who suffer from homelessness, substance use disorder, or mental illness are not debris; they cannot be 'swept' away," Rollins tweeted.

Walsh told Boston Public Radio that the city has not deviated from its investment in recovery resources, but he noted there is a gap in care.

"When somebody goes into detox, that's basically just to get the drugs ... out of your system. The next step is you want to get them into a halfway house, long-term sober living," he said. "We don't have enough long-term recovery beds available."

Walsh said the city has included a 35 percent increase in its budget for recovery services this year and noted his efforts to rebuild the Long Island Bridge, the site of a former shelter and treatment center, which has garnered intense resistance from Quincy officials.

Boston Mayor Marty Walsh joins Boston Public Radio monthly for the recurring segment Ask The Mayor, where he also takes listener calls.