The teacher, unable to control the group of students, remains totally calm

He also demands that the teacher 'sit your a** down' during the incident

In the short clip filmed in 2011, a student holds a desk chair above her head

Footage of the teacher being accosted by students was uploaded online

Frightening footage has emerged of a group of American high school students subjecting a despondent teacher to a barrage of abuse and intimidation inside the classroom.

In the short clip, an out-of-control student can been seen throwing things at her, telling her to 'sit your a** down' and threatening her with a chair.

While he continues to provoke the teacher, others in the room laugh and encourage him.

The student was recorded turning the classroom into chaos - his behavior was caught on camera

At one point during the incident he claims he is going to 'smack her a** with a whole bag of M&Ms'

In another, he picks up a desk and chair and holds it above her head. The teacher is seated just out of frame

The despondent teacher (pictured) is unable to stop the out of control students, and appears weary

Having lost control of the classroom, the teacher can do little to stop them - but remains calm in the face of their terrifying behavior.

The footage was filmed on a cellphone by one of the students at Chicago Vocational Career Academy in 2011.

The video shows one student repeatedly trying to make his way towards the teacher, who is sitting at her desk, as his friends hold him back.

He can be heard saying: 'What I say something I mean it. Now ask me what my name is again.'

Seconds later, he picks up a chair and desk and holds it above her head in a threatening manner - before later joking he is going to 'smack her a** with a whole bag of M&Ms'.

Although little effort is made to stop the student, she does offer some calm protestations.

When he throws several unknown objects towards her, she asks him to get rid of 'whatever you're throwing'.

At one stage, she also turns to the student filming the incident, stating: 'Young lady I'm going to have to ask you to have a seat.'

Later in the video, the student stands beside the teacher and tells her to 'sit your a** down'