A teaching assistant sent a bomb hoax to a school from a pupil's email account, a court heard.
Zoe Gregory, 26, pleaded guilty to threatening to blow up Ormiston Victory Academy in Costessey, near Norwich, in February.
The married mother-of-two made the threat after gaining unauthorised access to an email account belonging to student Holly Littlefield.
Holly, 16, and Vicky Francis, 15, were arrested and held in police custody for 10 hours after the scare.
Norwich Magistrates' Court heard how fellow pupils called the students 'terrorists' and dubbed Ms Littlefield 'Holly Bin Laden"
But it later emerged that Gregory was responsible for the threat, which she made without the students' knowledge.
Prosecutor Lisa Britton said both girls had been left distressed by the ordeal.
Ms Britton told the court: "The most important aspect is the impact on the girls. They were arrested, knowing they had done nothing wrong.
"They spent more than 10 hours in custody and must have been very distressed."
In a statement read to the court, Ms Littlefield said: "I was crying and distressed at being held in a cell."
Chris Brown, mitigating, said Gregory acted out of 'sheer desperation' after being 'plagued by post-natal depression'.
She sent the bomb hoax email to her own work account and then reported it to the school's principal, who contacted police.
Mr Brown said: "If she had known at the point of pressing send what her actions would have led to, then of course she wouldn't have done it.
"It was an extraordinary act and reckless stupidity born out of sheer desperation."
A spokesperson at Victory Academy said: "The safety and wellbeing of students is always our number one priority.
"We have been co-operating fully with the police with their investigations into this matter.
"Appropriate processes have been followed throughout and we can confirm that the staff member involved no longer works at the school.
"We continue to do everything we can to support the children involved.
Speaking after the case Vicky told her local paper: "When I got arrested I didn't know what was happening until I got down there and they explained what was going on.
"I was standing there shaking because I didn't know what was happening. I've never been in that position before. No-one told me what I had been arrested for - I've never been as scared in my life as I was that day."