Deleting text keyboard shortcuts in Safari with an external keyboard

I’m still finding my way around a new iPad, which I primarily use with an external keyboard. As far as I can tell the keyboard shortcuts for Cmd+Delete and Control+Delete don’t work in Safari’s text fields, although they work in Ulysses, 1Writer and other dedicated text editors. Is this just an omission on Apple’s part or is there something I can change/setup to get these?