How to delete FortiGate log entries stored in memory or local disk fortigate 300C firewall

How to delete FortiGate log entries stored in memory or local disk.
It is assumed that memory or local disk logging is enabled on the FortiGate and other log options enabled (at Protection Profile level for example).

• 1- Example to delete logs from local disk for only WEB Filtering entries (*):

FGT# execute log filter device 0

FGT# execute log filter category 3

FGT# execute log delete
This will delete webfilter log
Do you want to continue? (y/n) y

• 2- Example to delete logs from memory for only WEB Filtering entries (*):

FGT# execute log filter device 1

FGT# execute log filter category 3

FGT# execute log delete
This will delete webfilter log
Do you want to continue? (y/n) y

• 3- Example to delete all local logs ( memory and local disk ) :

FGT# execute log delete-all
This will delete all local logs
Do you want to continue? (y/n) y


(*)_Note : To get the device and category list, type the filter command without argument .

FGT# execute  log filter device
Available devices:
 0: disk
 1: memory
 2: faz
 4: fds

FGT# execute  log filter category
Available categories:
10: application control
 9: dlp
 6: content
 5: spam
 4: ids
 3: webfilter
 2: virus
 1: event
 0: traffic