What is the best approach to search when offline?

The mobile application has a search catalogue feature. Every search is sent to the server, and there are no local search results. This means that when the user's mobile device is offline or in airplane mode, the search feature is unavailable.

How should the search be treated and how to let the user know how to fix their connectivity? What is the most expected behaviour? Also, we're open to suggestions.

Current options:

  1. Disclaimer notifying the user's offline connectivity (Favorite option, it's simple and not overwhelming)
  2. Disable search bar (My concern is this will make the user think the application is broken when the only problem is their connectivity)
  3. Disclaimer notifying the user's offline connectivity AND disable search bar (Seems to be an overkill)