The skirmish between Empire and Rebel Alliance which took place sometime after Rebels liberated the planet of Onderon

Onderon Planet

from Empire. Empire retaliated and as part of their intimidation tactics they started to instigate forest fires around the planet. Rebels sent a squad led by veteran trooper Fenn Signis

Fenn Signis (Human) Character Minor Characters

to prevent brushfire but when they arrived they encountered heavy resistance from Imperial forces. Signis quickly discovered that Imperials planted four sets of explosives to start forest fire when detonated, and he decided that the only way to save the forest from complete annihilation is to to disarm explosives while defeating the Imperial forces protecting the site. The empire forces were composed of several squads of stormtroopers

Imperial Stormtrooper Organization Galactic Empire Military

, scout troopers

Imperial Scout Trooper Organization Galactic Empire Military

squad with E-Web blaster, probe droid

Arakyd Viper Probe Droid Droid

and a lone AT-ST

AT-ST Ground Vehicle Vehicles

. As soon as Rebels managed to destroy AT-ST using those same explosives that Imperials have planted, a squad of Trandoshan

Trandoshan Sentient Species

hunters arrived on the battle scene. It took Rebels all they had to defeat combined forces of Imperials and their Trandoshans allies, and then drove the rest of the Imperials into a full retreat.
Notes
1. It is unclear if the liberation of Onderon which is mentioned in Imperial Alliance Core Set is somehow related to [Attack on the Imperial Army-Navy Ordnance Center>
2. This event took place after Rebels left their base on Arda I and definitely after Battle of Yavin

Battle of Yavin Event Galactic Civil War

.
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