A teenager has been arrested in Lancashire on suspicion of trying to incite racial hatred.
The 15-year-old from the Brierfield area was detained by police on Tuesday.
It is alleged he put up posters, carrying the letters BNP, on the back window of a school bus that was carrying pupils home.
Officers from Lancashire Police boarded the bus and arrested the boy. He has been released on police bail.
The school is understood to be investigating the incident.
The teenager faces possible exclusion.