A teenager who set fire to his own room was behind bars today after a judge branded him a danger to the public.

Bradford Crown Court heard that Garth O'Hagan was 17 when he started the blaze at a semi-detached property in Gathorne Street, Great Horton, Bradford, run by the Lighthouse Project as a home for vulnerable young men.

He piled magazines, paper and a chair on to his bedding before setting it alight with a cigarette lighter, said prosecutor Nicholas Askins.

No-one was injured in the incident on January 3, but firefighters had to wear breathing apparatus as they battled through dense smoke to limit the fire to the one room. Fortunately, the other residents of the property were out at the time.

O'Hagan, now 18, pleaded guilty to arson being reckless as to whether lives would be endangered and also admitted an offence of threatening behaviour.

Imposing a sentence for public protection, Judge Robert Bartfield told O'Hagan he would have to serve at least 18 months before being able to apply for parole.

"You were involved in a fight with a young woman, which left you in an angry and violent mood," the judge added. "You then, in your room, set a deliberate and careful fire."

A psychiatrist had concluded that O'Hagan was suffering from an anti-social personality disorder and there was a risk of him committing similar acts in future.

"This was no casual dropping of a match," said the judge. "You do pose a significant risk to members of the public. I have to have in mind the protection of the public. You will be released when it is decided that would be safe."

Mr Askins told the court that before starting the fire O'Hagan smashed crockery in the kitchen and smeared blood on the wall. Afterwards, he went outside and placed his belongings in a wheelie bin, before going to a nearby property and casually telling some friends that he had set fire to his home.

He later threatened a worker with the Lighthouse Project and when police arrived he threatened to strangle the officers.

Rodney Ferm, for O'Hagan, said his client was not a firebug and was not mentally ill.

"He felt he had been roughly treated earlier that evening and this was his response."