I don't really know since I haven't watched the anime in a while, but given that the manga is only on day two of the war, the producers/writers probably saw a need to delay the main story in the anime a little more.
If I recall, it was said that all of April's anime would be filler; I didn't hear it from a direct source, but it seemed to be a general consensus here on NB, so I assumed that was what it was. If that's true, next week's episode will be a continuation of the story.