A 14-year-old boy who stabbed his supply teacher in a row over a mobile phone as other pupils watched will be sentenced later this year.

The teenager, who cannot be named, today denied attempting to murder Vincent Uzomah at Dixons Kings Academy, in Bradford.

But he admitted a charge of causing grievous bodily harm with intent - a plea prosecutors at Bradford Crown Court said they accepted.

A previous hearing heard how the boy bragged about what he had done on Facebook, but later told police in a statement: "I am sorry for stabbing my teacher. I do not know what is wrong with me"

Mr Uzomah had only been teaching at the school for a few weeks when he was attacked by the teenager as the lesson began at the start of the school day on June 11.

Earlier this month, a youth court heard how the defendant argued with the teacher over a mobile phone after Mr Uzomah asked him to hand it over.

During the confrontation, the 50-year-old teacher was stabbed once in the stomach by the teenager, who immediately fled the school grounds, scaling a fence.

He was stabbed with a kitchen knife the boy had brought from home.

The boy was arrested by police in the city centre following a six-hour search - a move caught on mobile phone video by bystanders.

The teenager then boasted on Facebook: "The mother****** getin funny so I stick the blade straight in his tummy."

Today, the boy sat in the dock flanked by two security guards and was wearing blue jeans, grey shirt and black puffa-style jacket.

He said "yes, sir" when he confirmed his name and spent much of the rest of the 11-minute hearing with his head bowed.

No details of the stabbing incident were mentioned in court today, but Judge Jonathan Durham Hall QC said: "This is a very troubling case."

He said the boy was "undoubtedly a very troubled young man" and said Mr Uzomah was "a very brave and compassionate victim".

Judge Durham Hall said a psychiatric report and a pre-sentence report needed to be prepared before sentencing could take place.

He said he agreed with the Crown Prosecution Service's decision not to proceed with a charge of attempted murder, saying it would be very difficult to prove the defendant had an intention to kill.

As the boy left the dock the judge thanked him.

He said: "Your plea has been noted, very proper, at a very early stage. Thank you."

The boy was watched by two members of his family from the public gallery as he was led away.

Mr Uzomah was not in court.

After the incident at the school Mr Uzomah was taken to hospital, but released a few days later following surgery.

He later issued a statement thanking people for their support.

He said: "I wish to express my heartfelt gratitude to God and to everyone for all the support that myself and family have received during the course of the traumatic event of my life.

"It has been 12 days since this event occurred and I thank the Lord Jesus for sparing my life."

Mr Uzomah, who has worked as an extra on the soaps Emmerdale and Coronation Street, thanked the doctors and nurses who helped him and the staff at the Dixons Kings Academy.

He said: "My family and I appreciate the overwhelming support, love and care that we have received from friends and well-wishers, as I continue on the path towards recovery. Thank you, all."

His casting agency said: "Vincent is a very nice, reliable, bubbly guy. He's genuine and easy to get on with."

The attack on Mr Uzomah caused shock in the Lidget Green area of Bradford where it happened. It took place only 15 miles from Corpus Christi Catholic College in Leeds, where veteran Spanish teacher Ann Maguire was stabbed to death in April last year.

Will Cornick was jailed for life and ordered to serve a minimum of 20 years before he is considered for release for murdering the 61-year-old teacher when he was 15.

The teenager was remanded in custody today by Judge Durham Hall and will be sentenced later this year, probably in August.