Five children in the United States, aged 10 and 11, have been arrested for planning to "explode" a fake bomb in their school.
The alleged threat was exposed after teachers found a letter with details of the plan and alerted the police.
Channel 12 news in New Jersey said the four girls and a boy carried an "artefact" to their school, which they allegedly planned to detonate the same day.
However, the item only contained vinegar and cinnamon.
But the police believe the plan was not a prank and the students wanted to "cause damage", although their motive was still unknown.
The children have been suspended from school after being arrested and questioned by the police.
They have not been charged.