An Oakland high school student says he was called to the principal's office and then roughed up by school security guards who moved out of view of security cameras on purpose.

School surveillance video captured the Jan. 8 confrontation between 16-year-old old student Roberto Canales and an officer at Fremont High School. The incident comes two years after two guards accused of punching and choking a student in the same office resigned.

Through a translator, 16-year-old Roberto Canales said it all started when he was summoned to the principal's office and told them he wasn't feeling well.

"They told me I was not able to go home because of the situation," Canales said. "They said to me, 'Why was I selling drugs at school?' And 'Why was I carrying a gun?'"

He says he wasn't doing either. In the video, the guards can be seen forcing Canales around the corner, out of the view of the camera. That's when he says they handcuffed him.

"They hit my head. My back. My back hurts," Canales said. He said the confrontation left him with a bruised eye, red marks, and scratches on his wrist and shoulder.

Thursday, Oakland Unified Police Chief Jeff Godown spoke with NBC Bay Area's Elyce Kirchner about the incident.

Kirchner: Is there any possibility that those security guards knew where that security camera was located and therefore then moved the child?

Godown: If you are asking if the security guard intentionally took that kid around the corner so he wouldn't be caught on camera, the answer is no.

Two years ago, in the same office, the same camera caught two guards punching and choking a different student. Those guards resigned. Godown says this incident is different.

"He could not leave that location," Godown said. "He was a danger to himself." That's because medical records show Canales was under the influence of cocaine at the time of the confrontation, which the teen denies.

The January incident is under investigation. Godown said, if a student is a threat to himself or others, security guards are allowed to physically restrain a student, which he says was the case in this incident.

The security guards involved are back at school.

The school district police department employs about 90 security guards throughout the district, with five or six stationed at each of the high schools. The guards are embedded in the schools and liked by many students there, but occasionally have to get physical with students, such as if they need to break up a fight. The guards are unarmed and carry only handcuffs.

"They have a very tough job," Godown said.

Editor's Note: NBC Bay Area is naming the 16-year-old in this case with his legal guardian's permission.

Bay City News contributed information to this report.