Adam GrettonA teenager was today detained under the mental health act after he threatened to burn down a Norfolk high school. The 16-year-old had made threats on the internet which were picked up by someone in Canada who alerted Norfolk police.Adam Gretton

A teenager was today detained under the mental health act after he threatened to burn down a Norfolk high school.

The 16-year-old boy was arrested at about 11.30am yesterday after entering Attleborough High School armed with a knife, matches and a canister of what was thought to be flammable liquid.

The youth was detained after police received a tip-off from Canada that the teenager was about to vandalise his school

Superintendent Katie Elliott, of Norfolk Police, said they were alerted by a member of the public from Canada who had seen a threatening message posted on the internet.

She praised the actions of the informant had no links with the school but, had called the force switchboard after becoming concerned.

'The constabulary was alerted by a member of the public after a message was posted on a website inferring the criminal damage of Attleborough High School.

'When the individual attended the school, the youth's bag was confiscated. Inside, a knife, matches and a canister of what is believed to be a flammable liquid was discovered.

'Our officers immediately arrested the 16-year-old male, who is helping us with our inquiries.'

She said all pupils had their bags searched as a precaution but nothing further was found.

Police said the boy's home address was searched following his arrest and a computer was seized and sent for 'urgent analysis'.

The youth was detained over threats to commit criminal damage and possession of an offensive weapon.

Supt Elliott added: 'We are in the very early stages of a serious investigation into a serious offence where a young man is in custody. At the same time we want to reassure the public and pupils that their safety has been paramount.'

'It is an isolated incident in Norfolk and it is not something that happens very often and we are confident that it is an isolated incident for Attleborough.'

'It goes to show that things written on the internet can be viewed across the world and we thank the person who has read this and done something about it,' he said.

Stuart Bailey, headteacher of Attleborough High School, said that the incident had been dealt by senior school staff in a 'professional and calm manner.'

'We had been made aware of the student's alleged intentions and stopped him before he entered the main school site. I am very grateful to the person who did the right thing and made us aware.'

'School security is of paramount importance at Attleborough High. Whilst yesterday's incident is clearly not welcome, I am pleased with the manner in which it was dealt with both by my staff, and by Norfolk Police.'

'We have kept children and parents informed as soon as we have been able to, but I hope parents understand we are bound by the nature of an ongoing police investigation,' he said.