Mayor Bill de Blasio plans to release 40 inmates from Rikers Island amid a coronavirus outbreak in the five boroughs, he announced Thursday.

The 40 inmates had been put on a list for release, and the city is awaiting sign-off from prosecutors to approve the measure, Hizzoner said at an afternoon press briefing.

The inmates could be set free as early as Thursday, and the city will review more potential prisoners to let go as the outbreak continues in the coming days.

Earlier Thursday, three additional correction officers at Rikers Island tested positive for the deadly virus, and at least eight prisoners were being held in an infectious disease unit after showing symptoms of the disease.

The top doctor on Rikers warned in a series of tweets Wednesday night that a “storm is coming” to the island if the city and other officials don’t act to stop the spread in city jails.

“A storm is coming and I know what I’ll be doing when it claims my first patient. What will you be doing? What will you have done? We have told you who is at risk. Please let as many out as you possibly can,” Ross MacDonald, the chief medical officer for Correctional Health Services, wrote.

On Sunday, a civilian investigator for the department of correction on Rikers Island died after contracting coronavirus — the first city worker to succumb to the virus.