A video showing teenagers allegedly assaulting a 69-year-old man, knocking him unconscious, has made its rounds on social media and has led to the arrest of five minors.

The video was shot Tuesday outside a Cupertino McDonald’s off North Stelling Road. Deputies said a man saw the teens in the crosswalk and told them to stop horsing around because they could get hurt.

That’s when one of the teens allegedly spit on the man and seconds later, they assaulted him, deputies said.

"Someone is essentially being attacked, that is the age of their grandfather," said Reginald Cooks from the Santa Clara County Sheriff’s Office. "Someone who was initially reaching out to them because he was probably concerned for their wellbeing."

Nearby Homestead High School helped deputies identify the five students and on Wednesday afternoon, another widely-shared video showed them walking off campus in handcuffs.

One of the suspect’s fathers shared a third video which appears to show the man holding onto one of the students, arguing the man could have diffused the situation.

"It’s still an open investigation so anyone with any video we ask that they come forward and give it to the Sheriff’s Office," Cooks said.

Investigators said the victim has moderate injuries to his face that are not considered life-threatening.

Since the incident occurred during school hours, the Fremont Union High School District is involved and in a comment said it will consider any disciplinary action once the Sheriff’s Office’s investigation is complete.

"Because there is an open law enforcement investigation and we have a responsibility to protect both the minors and the victim involved, we may not be able to share much information," Homestead High’s Principal Greg Giglio said in statement to parents.