The suspected shooter told investigators he did it in the name of the Islamic State in Iraq and Syria (ISIS).
"There was a terrorist attack yesterday, in the city of Philadelphia. A terrorist attack," Rubio told supporters at an Aiken, S.C., town hall, according to CNN.
"He walks up to the car and starts firing shots. They arrest him, he tells them, he confesses, 'I did it in the name of ISIS,' " added Rubio, a Republican presidential candidate.
“And then, [Philadelphia Mayor Jim Kenney] gets up and says, 'This has nothing to do with Islam and radical Islam.’ ”
The suspect waved down the police officer's cruiser Thursday night, officials reported, and opened fire when the car pulled over.
Capt. James Clark told reporters on Friday that the suspect said he "pledges his allegiance to [the] Islamic State, he follows Allah, and [that] is the reason he was called upon to do this."
Rubio on Saturday called it “ridiculous” to not take the shooting as Islamic terrorism.
"This is a radical person, living in United States, who became radicalized,” he said. 
“This is the new face of the war on terror, and it is dangerous and we need to confront it and defeat it. I will not stop until we do."