Mayor Bill de Blasio was ripped Saturday for his tepid response to the savage slaying of four vagrants in Chinatown, as fed-up critics urged action instead of prayers to address the Big Apple’s mushrooming homeless crisis.

“We’re stunned and horrified by this senseless act of violence against the most vulnerable members of our community,” de Blasio tweeted Saturday afternoon. “It flies in the face of the values of our city. We’re keeping the victims and their loved ones in our hearts.”

Critics said words are simply not enough.

“Keeping victims in your heart doesn’t seem to be working,” @JoshuaMansbach wrote. “Can we go back to letting the police do their jobs and PREVENT crimes from happening BEFORE they take place? Funny how you mock the thoughts and prayers after mass shootings, but do the exact same thing after crime in NYC.”

Another person pointed out that de Blasio, a failed 2020 Democratic candidate, said “on the campaign trail . . . ‘prayers aren’t enough!’ Now you move the words around a bit & say you keep the victims and their loved ones in our hearts today,” @KatisSophia tweeted. “YOU DON’T HAVE A HEART!!!!”

Others blamed de Blasio’s policies for the weekend carnage.

“Congratulations, another violent act that proves this city isn’t safe and crime is going up!” @BigJohnBklyn tweeted. “You can play with the numbers but you can’t hide the body count! Thanks Bill for destroying our city!”

The Sergeants Benevolent Association took de Blasio — and wife Chirlane McCray and her embattled mental health program ThriveNYC — to task.

“Hey Charlene[sic] and Bill,” the SBA tweeted. “Hows[sic] that mental health program working out for you in the safest city in America?”