ALLENTOWN, Pa. -

Lehigh Valley street gang members may be targeting New Jersey cops for revenge killings, according to an FBI memo obtained exclusively by 69 News.  The threat comes less than a week after police killed a suspect who murdered a Jersey City police officer in an ambush attack.

As hundreds lined the streets Friday to remember fallen Jersey City Officer Melvin Santiago, fellow officers remained on high alert.  The FBI's New York office has issued a warning about Bloods gang members, including two from the "Allentown-area," plotting revenge killings on cops.

Citing "an established Source with excellent access," the FBI document claims two "G-Shine Bloods gang members … both originally from the Pink Houses in Brooklyn, New York, now residing in the Allentown-area, have 'given the green light to kill LEOs [law enforcement officers] for killing a homie in Jersey City.'"

The FBI's Newark, N.J., office verified the authenticity of the memo, but would not comment further.

Jersey City's mayor responded to the threats.

"Any time there's a police shooting, police departments get threats against police officers that come in, and 99.9 percent of the time, they're unsubstantiated and non-credible," said Mayor Steve Fulop.  "We take every one seriously."

According to the FBI memo, gang members may target single officers guarding highway construction sites.

Earlier this week, the New York Post reported a similar warning from New Jersey State Police.  A law enforcement told the newspaper that out-of-state Bloods members were threatening to "kill a Jersey City cop and not stop until the National Guard is called out."

"Gang members are able to travel both nationally and internationally, and on occasion, you'll get some that would like to respond to that sort of thing," said Mike Knox, a nationally-recognized gang violence expert based in Texas.  "With gangs, unlike the true organized crime ... no one actually orders the hit; they just put a call out for that sort of thing."

A Jersey City officer now faces disciplinary action after discussing Bloods threats on his Facebook page.

While the FBI memo says this information is from a credible source, it also says agents are not aware of any specific plots.