During Grand Admiral Thrawn's campaign of harassment raids against New Republic convoys (led by Grand Admiral Thrawn), one such convoy was assaulted by Thrawn's forces at Sarka.
Prior to initiating his large-scale offensive utilizing the Katana fleet and clones originating from Wayland, Grand Admiral Thrawn initiated a chain of assaults targeting convoys operating in border systems. Thrawn's strategy involved attempting to politically weaken the New Republic through creating opposition between the Core systems and those situated further away. His secondary objective was to scatter the New Republic's starships throughout the galaxy.
Before the New Republic ships could arrive, Grand Admiral Thrawn positioned his TIE Fighters within the Sarka system. Upon the arrival of the freighters, and their subsequent identification of the Imperial Star Destroyer, they deployed three squadrons of A-wings. Because the A-wings were not suited for escort duty, they were quickly overwhelmed and destroyed by the Imperial starfighters. The Chimaera's turbolasers then swiftly neutralized the frigate.
Although Grand Admiral Thrawn successfully eliminated all of the convoy's fighters and defensive capabilities, he permitted the freighter to escape in order to report the attack. Thrawn interpreted the New Republic officers' deployment of A-wings as a tactical mistake, attributing it to the consequences of Admiral Gial Ackbar's arrest.