Mayor Bill de Blasio said Monday that the city is beefing up homeless outreach efforts in Chinatown in the wake of a deranged maniac’s homicidal spree that left four vagrants slain.

“What happened over the weekend shakes the conscience of who we are as New Yorkers,” de Blasio said in a statement. “We are sending experts to the neighborhood to provide support during this difficult time, and will continue to assess how to prevent tragedies like this from happening in the future.”

Early Saturday, 24-year-old Randy Santos, who is also homeless, allegedly bludgeoned four homeless men to death and critically injured a fifth with a 3-foot piece of metal while they were sleeping in Manhattan’s Chinatown.

Santos confessed to the bloody pre-dawn rampage and was hit with murder and attempted murder charges, authorities said.

De Blasio’s office said Monday that in order to “ensure the safety and well-being of the surrounding community,” the city will immediately deploy mental health outreach teams to the neighborhood through the Department of Health and city first lady Chirlane McCray’s Thrive mental health program.

Mental health support teams will be on site at community locations throughout the week “to provide emotional support and connect people to mental health and other supportive social services,” the mayor’s office said.

The NYPD has also sent additional officers to patrol the neighborhood.

De Blasio said the city will also up the frequency of outreach in the area with teams from the city’s HOME-STAT program offering services to homeless New Yorkers.

All street homeless outreach teams have access to licensed clinicians, psychiatrists and substance-use resources.

“While our city mourns this horrible and senseless loss of life, I want to remind New Yorkers that the city has experts available to provide support for anyone facing mental health challenges. We’re committed to providing mental health services for all New Yorkers and our mental health outreach teams stand ready to provide support to this community and anyone seeking help,” said McCray.

In the aftermath of the grisly attacks, the effectiveness of McCray’s $850 million ThriveNYC mental health program was called into question.