The mayors of New York City and Washington, DC urged their cities’ homeless populations to seek shelter Sunday as a “cold-blooded killer” who had shot at least five vagrants remained on the loose.

A lone gunman is suspected of targeting sleeping homeless men in a series of shootings in DC and the Big Apple this month that has so far left two men dead and three others wounded.

New York Mayor Eric Adams and DC Mayor Muriel Bowser said they were coordinating with federal authorities to investigate the crimes before he strikes again.

“The work to get this individual off our streets before he hurts or murders another individual is urgent,” the two said in a statement released just before midnight.

“As our law enforcement agencies work quickly with federal partners to locate the suspect, we are also calling on unsheltered residents to seek shelter. Again, it is heartbreaking and tragic to know that in addition to all the dangers that unsheltered residents face, we now have a cold-blooded killer on the loose, but we are certain that we will get the suspect off the street and into police custody.”

The gunman is suspected in three attacks on homeless men in DC between March 3 and March 9, with one man dying from his wounds. The same man made his way north to Manhattan by Saturday, when cops said he shot two homeless men in separate incidents in Soho.

Another homeless man found was dead in a sleeping bag in Tribeca, but authorities haven’t confirmed his death was related to the serial shooter. No ballistics were found at the scene and there were no discernible entry marks through the man’s clothing, sources said.

The NYPD issued new patrol guidance amid the terrifying incidents, an internal memo showed. All officers were directed to “proactively engage with apparently homeless individuals,” conduct wellness checks and offer shelter services.

Cops should also tell vulnerable people about the brutal attacks and show them wanted posters of the suspected gunman, the guidance said.