During the war, civilians were evacuated to underground bunkers to shelter from air raids.

bunkers 是名词 bunker 的复数形式。bunker 指"掩体、地堡"，特指用于军事防御或躲避空袭的地下坚固建筑结构。这个词源自苏格兰语，原指"储存煤炭的仓库"，后来引申为军事用途的防护设施。