A 13-year-old boy has been arrested in Sheffield following social media posts encouraging schoolchildren to engage in violent behaviour.
The child is being held on suspicion of malicious communications, encouraging or assisting crime and an alleged public order offence.
It follows a national trend involving so-called 'red vs blue school wars' posted on social media.
On Friday, South Yorkshire Police said it was increasing patrols following the circulation of posts in the region.
In a statement on Facebook, the force warned about "a reckless attempt from mindless individuals to incite meaningless violence", although at the time it said there were no confirmed reports of criminal offences or injuries linked to the trend.
Following the arrest, Inspector Katie Hammond said officers had "been actively monitoring social media and carrying out intelligence checks, and doing all we can to track down the accounts responsible and shut them down".
"I believe the overwhelming majority of children here in South Yorkshire understand this trend is reckless and irresponsible, and not at all reflective of the real, positive relationships which exist between our educational establishments, young people and communities," Insp Hammond added in a statement.
The national trend, which first emerged in London last month, involved social media posts advertising so-called 'red vs blue school wars', encouraging confrontation between students from different schools.
Read more from Sky News:
Man charged with Ian Huntley's murder
Glasgow fire - what we know
Gamers could get compensation
It prompted the Metropolitan Police to launch Operation Cedarfield, an initiative to tackle violent school gatherings across London.
On 1 March, the force confirmed officers arrested "two individuals in Central East London in connection with a recent trend of social media posts".
"Both suspects, a man aged in his 20s and a boy aged 15, were arrested on suspicion of encouraging or assisting in a crime," the statement added.
(c) Sky News 2026: Boy, 13, arrested in Sheffield over social media posts encouraging school violence
Six dead and five injured in 'deliberate' Swiss bus fire
Jury trial changes survive Labour rebellion to clear first Commons hurdle
Queen supports abuse survivors in speech seen as reference to 'Epstein issue'
Labour MP says her rape case took 1,088 days to reach court
Teen's headache before death in suspected holiday park carbon monoxide poisoning
Mother speaks out after son fell to his death in high-rise railing incident
How AI can identify breast cancer 'better' than a doctor but there's a catch
Australia grants visas to more members of Iranian women's football team
