I need to block the app. Which domain names does it use? Can I use content restriction like Safari? Can I block the IP addresses in my router?
If you want to prevent usage of the app completely, you can enable restrictions (Settings > General > Restrictions) and turn off the toggle for News.
iOS 10 also lets you delete default apps like News, but keep in mind that it could be re-downloaded from the App Store (unless you enable the restriction for Installing Apps too).