Police say they are working closely with the school following the incident on Monday 10th December.
Officers were called into St Michael's C of E in Heavitree on Monday.
The knife was not taken out of the child's bag until it was confiscated by staff at just after 9am.
Devon voters go to the polls
A third of Plymouth City Council seats are up for grabs
Clyst valley park could double in size
Residents will have their say
Multiple arrests made in Exmouth
Patrols stepped up to tackle big issues
Devoncast - Exeter Pride, Torbay tourism and Tavistock trains
Devoncast features the latest news and views from around Devon
Sid Valley Radio joins East Devon broadcast bid
New digital stations planned for East Devon
Radio Exe newsreader to abseil down Exeter Cathedral
Josh Tate will descend over 100 feet on Saturday
