Two teens have been arrested after hundreds of schools and colleges received threatening emails.
Wigan schools have been on high alert twice in the past few weeks after establishments across the UK received threatening emails.
An investigation was launched into the incident and two separate arrets have been made, one coming just a day after another round of "malicious" emails was sent out.
Several Wigan schools including The Deanery High School and St Mary's CE Primary School, took action to protect their students yesterday after an email was distributed threatening that children would be "hit by a car".
The National Crime Agency (NCA) said it was believed the incident was linked to a hoax bomb threat that closed hundreds of schools last week.
An 18-year-old man was arrested by Hertfordshire Police and the NCA in Abbots Langley on Wednesday night on suspicion of making malicious communications.
A spokesman for the NCA said: "We understand these threats have caused considerable concern but we do not assess there to be an increased risk to the public."
A 19-year-old man was arrested in Watford last Wednesday on suspicion of blackmail and making malicious communications after the mass bomb hoax.