Good news was sometimes released prematurely,with the British recapture of the port announcedhalf a day before the defenders actually surrendered.

译文：

好消息有时会提前发布，英国夺回港口这一消息就是在占领者真正投降的半天前发布的。

点睛：

with引导的介宾短语作整个句子的状语，其中announced为British recapture of the port的后置定语，两者之间为被动关系。before引导时间状语从句限定动作announced发生的时间。