Autistic 7 year old and throwing

Hello 

My 7 year old son with Autism has recently started throwing objects at home but much more so in school.He is not throwing at people, just into open space around him.He attends a mainstream school and has a ta he shares with another autistic child.

We are just wondering if anyone else has experienced this or if anyone has any tips on how to help him stop this behaviour as we are concerned it is only a matter of time before he accidentally hurts someone.

Thankyou