A 16-year-old has been sentenced to four-and-a-half years in youth detention after he attacked a teacher at Milford Haven School, while armed with a knife in a classroom.

On February 5 this year, the teenager, then aged 15 – who cannot be named for legal reasons – followed the victim into a classroom and asked for help with schoolwork, before then attacking her.

The teacher Vicki Williams (pictured) was able to disarm the teenager, however sustained injuries requiring hospital treatment. Fortunately, she was able to make a recovery after treatment.

In July, the boy was found guilty of wounding with intent. He had previously pleaded guilty to being in possession of a knife.

During the trial, Williams said the attack "came out of nowhere" after the boy asked her for help with his work at the end of the school day.

He closed the classroom door behind him and Williams noticed him looking through his bag as he asked her if his work "was correct".

She said he suddenly pulled a large kitchen knife from the bag, and stabbed her in her head.

Williams grabbed the knife, pushed the boy back with her legs, and screamed.

During the sentencing hearing, the court heard Williams did not know if she would be able to return to work.

She is due to start therapy for post-traumatic stress disorder (PTSD), and said in her victim personal statement that she felt "sadness, anger and guilt" after the incident.

She said she had returned to the school with a colleague during the summer holidays, and had realised how closely she had been "pinned" to the wall behind her desk.

During the trial, a colleague who rushed to help described Williams's screams as "gut-wrenching".

CCTV footage showed the teenager running away from the school after the attack.

He was later detained at his grandmother's house.

The boy told the jury he had brought the knife to school as a game with his friends, which involved bringing "random household objects" to see what they could "get away with".

He said the incident was "an accident"

Following sentencing, Senior Investigating Officer, DI Sarah Totterdale said: “Following this awful incident in February, our officers quickly attended the scene at Milford Haven Comprehensive School along with other emergency services, and a lockdown was implemented.

“Shortly afterwards, we managed to trace and arrest the then 15-year-old boy, who was subsequently charged on February 7.

“The victim in this case has shown immense bravery, and to re-live the events of that day during the trial must have been incredibly traumatic. We are thankful for her assistance in this investigation, and hope that in time she can obtain closure from this ordeal.

“We are also grateful to teachers and students of Milford Haven Comprehensive School and the local community, who will also have greatly felt the impact of this incident.

“Finally, thank you to our emergency service partners and Pembrokeshire County Council for their assistance, and members of the wider community for their support.”