Onlookers were left 'shocked' after watching a group of parents at a Northampton school 'shouting out abuse'.
In a letter sent out yesterday (Tuesday), Chiltern Primary School headteacher Penny Howell criticised parents for continuing an 'external dispute' in her school grounds while using 'threatening language and behaviour'.
The letter said: "Whatever may have heppened outside school, it should not negativley affect our other families.
"Having spoken to some parents directly after the exchange, I know they are shocked by such behaviour at Chiltern. This is not acceptable."
The incident has since been reported to Northamptonshire Police and the school is getting statements from parents involved and witnesses.
If any other parents have information about the incident the school is urging them to contact them with the next couple of days.
The letter continued: "I apologise to the families who witnesses this disagreement and want to reassure all of our families that this kind of behaviour is not tolerated within our school community."