A conservative author, radio host and an activist is warning fellow black Americans not to fall for Islam, saying they can't see what's really happening.

Jesse Lee Peterson said Muslims are taking advantage of angry and disenchanted black Americans as evidenced by Edward Archer, who shot a Philadelphia policeman last week and later pledged allegiance to the Islamic State and Allah.

"Because they're angry and in a fallen state, they don't see that these people are their enemies and not their friends," Peterson said on his radio show, according to WND.

He said, "Blacks have been told that Christianity is the white man's religion, Islam is the black man's religion, so jump onboard. And they're foolish enough to do it, not all, of course, but they're foolish enough to do it because they can't see what's going on."

Archer fired 13 shots at Officer Jesse Hartnett, who was taken to the hospital for treatment after suffering three gunshot wounds in the arm.

Peterson said Nation of Islam, the black Muslim organisation led by Louis Farrakhan, has been recruiting black inmates in prisons since 1984 with little pushback.

"Louis Farrakhan is an evil man, and yet he's allowed to recruit in this manner angry black men and now women, and so I'm not surprised that ISIS is able to do this," he said.

Fox News reported that Archer's brother believed Edward shot the officer out of anger at the alleged mistreatment of black men by police officers.

"This idea that black men are being mistreated by police officers is a lie, but it's been out there so long, no one has disputed it. And now this idiot believes it, as most black people do," Peterson said.

He is also blaming President Barack Obama for his support to "Black Lives Matter."

"I have to tell you, I blame Barack Obama as well because he has created this environment by confirming Black Lives Matter and all those idiots who have been going after cops," Peterson said, warning that "whether they are Muslim or not, you're going to see more and more of this."

Peterson said blacks' anger stems from the belief that white racism is the cause of their misery.

"They're first angry because of not having fathers in their lives, and then [they're] traumatised by their black mothers and grandmothers," Peterson argued. They have not been told how to get over that. They have been told that it's white racism. And when you're angry, folks, I'm telling you it is almost impossible to believe the truth."