The battle took place before they left the city.
But who could their enemies in Elpaxin be? Firstly, it is impossible for the military and the Silverwind Knights, as they don't need to resort to such methods.
Fang Hong first thought of the 'Big Sister' and her group they encountered at Traveler's Rest. They did have the motive and recognized Atira and Tianlan, but whether they had the strength to carry out such an attack was doubtful.
Then there was another potential enemy, the Jiefulite Red Cloak Team, descendants of Flor. The Red Cloak Team had the ability, but seemingly lacked the motive. Even if they saw the Continental League and recognized him, they did not know Atira and Tianlan.
Or perhaps the Dragon Worshippers—but this hypothesis was truly frightening to consider. They hadn't even formally started their investigation, and the enemy had already come knocking. Wasn't this going too far?