MIAMI » An internal affairs investigation was underway Friday after a 47-second video emerged showing a Miami police officer putting a handcuffed young man in the back of a cruiser and then jumping on top of him.

Shenitria Blocker told The Associated Press that she filmed the incident Thursday afternoon with her cellphone in Miami’s Liberty City neighborhood because she heard a commotion. She said she heard the young man asking the police officer why he was being arrested.

“The cop told him he didn’t have to tell him why he was being arrested, and the officer jumped in the car, got on him and hit the man a couple of times,” Blocker said Friday. “After that, another officer came up to me and told me to stop recording, that I can’t record.” She said that the officer slapped at her hand as they talked and that her mother took the phone and hid it.

Blocker said she doesn’t have a Facebook account, but her friend Marilyn Smith posted the video. It had about 80,000 views by 11 p.m. Thursday. It later was taken down.

Miami Police Maj. Delrish Moss said in a statement late Thursday that the department had viewed the video. Police have not named the officer involved or the young man who was arrested, but Moss said the officer’s gun and badge had been taken away until the investigation is completed. Police wouldn’t provide a specific age for the man who was arrested but said he is not a teen.

The video begins with officers standing around a car. A black officer escorts a handcuffed young black man into the back of the patrol car. At the 37-second mark of the video, the officer appears to leap on top of the man from the back passenger door. Someone appears to swat at the cellphone before the woman taking the video says, “Don’t touch my phone, baby, move.” The video then ends.

“We have launched a full internal affairs investigation into the matter,” Moss said in a statement. “We take that responsibility very seriously.”

The incident also caught the attention of police union president Javier Ortiz, who posted the video on his Facebook page and released a statement.

“While the video may seem concerning to some, the FOP (Fraternal Order of Police) is confident that when everything is analyzed within the totality of the circumstances, it will be concluded that the police officer was doing what he is supposed to be doing: Protecting our community,” Ortiz said.