Video stills of the attack as captured by fellow students. Photo: mmc-news.com

Spokeswoman Dena Iverson said the investigation will look into "the circumstances surrounding the arrest" to see if a federal law was broken.

The incident occurred at Spring Valley High School in Columbia when the unnamed pupil refused to leave class.

Video shows the officer knocking her down and pulling her across the floor.

The officer, Ben Fields, has been placed on leave and there has been an outcry from various civil rights and parents' groups.

Richland County Sheriff Leon Lott told a news conference that in one video the girl could be seen trying to hit the officer as she was being pulled to the floor.

However, he said the investigation would focus on the officer's actions.

"I think sometimes our officers are put in uncomfortable positions when a teacher can't control a student," he added.

The FBI, which will carry out the probe, said in a statement it would "collect all available facts and evidence".

'Egregious'

Tony Robinson, another pupil who recorded the video, told local media that the altercation began when the girl took her mobile phone out during class and would not put it away when asked.

School administration then summoned an officer, who asked the girl - who is African-American - to move. She replied that she had done nothing wrong, and then Mr Fields grabbed her.

"When I saw what was going to happen, my immediate first thing to think was, let me get this on camera. There's no justifiable reason for him as to why he did that to that girl," Mr Robinson said.

Mr Fields had been assigned to the school and was meant to protect pupils and teachers.

The American Civil Liberties Union (ACLU) said such "egregious use of force" against young people in class was "outrageous".

South Carolina's education superintendent expressed concern and the state's National Association for the Advancement of Colored People (NAACP) has said the officer should be charged.

The incident comes at a time of increased scrutiny of police and their use of force against African Americans.

One group, the Richland Black Parents Association, said the video "revealed what many African American parents have experienced in this district for a very long time".