Dear Manisha,
You cannot give warning to all. In such situation, an office circular is issued. Going further, why people make unwanted intra-company movements? Have you studied the reasons?
Earlier I have given exhaustive reply on similar query. Click the following link to refer it:
https://www.citehr.com/574084-loiter...ml#post2328218
I recommend you writing the circular on your own and uploading it here. Some senior like me will correct it. Earlier, I had helped in drafting the circular. It will be a good reference to you. Check the following link:
https://www.citehr.com/317584-i-need...employees.html
For the drafts of the warning, albeit for the different reasons, you may refer my following reply:
https://www.citehr.com/327002-warnin...ml#post1493525
Thanks,
Dinesh Divekar