Rebel fight among Federation and Rebel fleets

This random event occurs in:

The Long-Ranged Scanners will detect ship presence. This event can occur multiple times per sector.

The intro text for this event varies, and could be any of the following:

You arrive in the middle of a raging battle. Both sides are taking heavy losses. A small squadron flies past and a fighter breaks off, moving toward your position.
Two fleets fight nearby. You try to skirt around the edges of the battle and keep out of weapons range, but a Rebel scout spots you and moves in.
It's hard to tell who is winning the nearby battle. Before you have a chance to figure it out, a fighter moves in to attack.
The sheer scale of the destruction in the distance is almost breath-taking. Unfortunately, your position as an independent observer doesn't last for long!
The destruction in the distance is almost awe-inspiring. However you're dragged back to reality as Sensors indicate you are under attack.
You don't have any time to worry about the battle in the distance. The fight is coming to you really quickly!
- Fight a Rebel ship. (no surrender offers, no escape attempts)
  - (After destroying enemy ship) There's no time to salvage all of the wreck, the fleet is still nearby. Get ready to jump!
    - You receive low scrap.
  - (After killing enemy crew) There isn't time to salvage the enemy ship but your crew made off with a few nearby materials. Prepare to jump.
    - You receive medium scrap with resources.

Trivia[]

This event is called "BOSS_FLEETS_BOTH_FIGHT" in the datafiles.