美国警告各大城市在对伊朗核场所发动袭击后加强安全。 U.S. alerts major cities to increased security after strikes on Iranian nuclear sites.

美国国土安全部已发出警告, 在美国最近对伊朗核场地发动攻击后, 威胁环境加剧。 The U.S. Department of Homeland Security has issued a warning of a heightened threat environment following recent U.S. strikes on Iranian nuclear sites. 主要城市的地方执法机构处于高度警戒状态,尽管没有出现对祖国的可信威胁。 Local law enforcement agencies in major cities are on high alert, though no credible threats to the homeland have emerged. 该警报源自伊朗历史上针对美国领土上的政治人物以及针对美国目标进行网络攻击的历史。 The alert stems from Iran's history of targeting political figures on U.S. soil and conducting cyberattacks against U.S. targets.