Iphone 5 -- can't delete facebook inbox messages from phone even though they are deleted on my computer ???

Had the same problem too, the only way around it is to delete the app and reinstall.

If you are using an Iphone 5 or IOS 6.0

Go to the messenger app and then touch & hold the person's message you want to delete

soon you will see a popup option with (Archieve thread, Mark as Unread & Cancel) choose Archieve thread.

Then go and refresh your facebook app.

This is the only way to get rid of the messages in your inbox in facebook app.

If you are using an Iphone 5 or IOS 6.0

Go to the messenger app and then touch & hold the person's message you want to delete

soon you will see a popup option with (Archieve thread, Mark as Unread & Cancel) choose Archieve thread.

Then go and refresh your facebook app.

This is the only way to get rid of the messages in your inbox in facebook app.

Ok how to delete FB messages from your iPhone :

1. Log off the app

2. Open up FB from Safari

3. Archive messages( swipe message with finger for archive box to appear)

4. Go into archive message folder. Open message and swipe with finger Delete will appear- Press Delete