The two from a primary school in Warwickshire, England, poured a deadly bleach-like chemical into their teacher’s coffee flask while she had her back turned.
The 39-year-old teacher was about to take a sip of the poisoned drink when another pupil told her what had happened.
The students were suspended following the incident at Clapham Terrace Community Primary School in Leamington Spa.
According to reports, the pair belonged to a school gang calling themselves “The mafia.” They had drawn up a “hit list” of six teachers.
“The school has dealt with the situation appropriately and we’re hoping to move on. Neither the school nor the teacher are pressing charges,” Philip Robbins, the primary school’s chair of governors told The Sun.
The incident happened just days after the killing of a teacher in the city of Leeds, England.
Anne Maguire, a Spanish teacher with 41 years experience, was stabbed to death by one of her students at Corpus Christi Catholic College on April 28.
Last month, a national survey in Britain showed that nearly a thousand children had weapons confiscated on school premises over the last three years.