A judge has issued a stark warning to social media users not to prejudice the case of a 15-year-old boy accused of stabbing teacher Ann Maguire to death in her classroom.

Judge Geoffrey Marson QC said serious consequences could follow for individuals who named the teenager online or published other information covered by reporting restrictions.

He made the comments as he remanded the youth – who cannot be named for legal reasons – in custody at Leeds Crown Court today.

The teenager appeared by video-link 24 hours after he appeared yesterday at the city’s youth court accused of murdering Mrs Maguire, 61, as she taught a lesson at Corpus Christi Catholic College on Monday morning.

The boy had been widely identified on social media and was also named by The Sun newspaper this week prior to being charged.

The national daily has now removed all reference to his name from its website.

Judge Marson said journalists generally understood the restrictions that applied in the case but added: “What may not be understood by many is that these constraints and prohibitions apply also generally, including users of online social media sites and bloggers.

“They are just as much bound by these constraints as are the press. The consequences for individuals, I would emphasise, can be serious if there is a breach.”

Judge Marson said the youth will next appear at Leeds Crown Court for a plea and case management hearing on July 11 and fixed a provisional trial date for November 3.

The judge made an order giving the teenager anonymity under section 39 of the Children and Young Persons Act 1933, but amended it to make clear that the name of the school where Mrs Maguire was attacked could be named after Paul Greaney QC, prosecuting, agreed that it would be “absurd” not too identify it.