Parents have voiced fears after a poster circulated online urging pupils from schools in Northamptonshire to take part in organised violence.
The poster, which promoted a 'Northampton War', listed multiple schools in the area and encouraged teenagers to gather and "be violent".
Northamptonshire Police said they were aware of the post and warned that "anyone seen fighting or wielding weapons of any kind will be arrested".
Rebecca Birdsall, a mother of four, said the post left her "terrified" about her children's safety.
"Yesterday [Wednesday], my son's phone tracking went off and I went into massive panic mode because he was late home and I didn't know where he was," she said.
