bunker, incoming mortar alarm. 掩體, 迫擊砲報警

U.S. military personnel sit in a bunker as an incoming mortar alarm is called at a coalition air base in Qayara, some 50 kilometers south of Mosul, Iraq, Friday, Oct. 28, 2016. The U.S. military says Iraqi forces have retaken 40 villages from the Islamic State group near Mosul since a massive operation to drive the militants from the city began last week. It says Iraqi troops are consolidating gains made east and south of the city earlier this week, but insisted “momentum” was still on their side. (AP Photo/Marko Drobnjakovic)
Photos of the day – October 28, 2016
https://www.yahoo.com/news/photos-day-october-28-2016-172434154.html

Mortar (weapon) - Wikipedia

迫擊砲

Bunker是什么意思

 ① 掩体,地下室② (船上的)煤舱,粮舱,油舱;贮藏室③ (高尔夫球场上的)洞,障碍