Disclaimer: Viewers may find the video above disturbing.

Two teenagers are accused of beating a pregnant woman in Quincy, Massachusetts, and the savage attack was captured on camera.

Quincy College student Alec Zeng recorded shocking video Tuesday showing a woman screaming and being assaulted outside the post office on Washington Street.

"She was just screaming. Just like, basically telling them to stop," Zeng recalled.

Police say the victim and her boyfriend were outside the post office when she got sick on the sidewalk because of her pregnancy. They say words were exchanged, and that the two men spat on her.

"When I first opened the door, all I see is the guy spitting on her, and then just started throwing the punches," Zeng said.

Police arrested 19-year-old Tyrese Johnson and 18-year-old David Russel. Police say the woman was kicked in the stomach. The Norfolk County District Attorney's Office said she had to go to the hospital at least twice for a checkup on the baby.

Police and the victim were grateful Zeng was there to get the video and help authorities find who did this.

"I'm glad I did, cause they found the people," Zeng said. "The lady also thanked me, too. She said, 'Thank you so much,' and gave me a hug. I wanted her to be OK."

The woman's unborn child is expected to be OK, as well. Johnson and Russel are charged with aggravated assault and battery on a pregnant woman.