clamp down on: 施压于；压制

斯里兰卡外长卡迪尔加马尔8月12日深夜在其位于科伦坡的住宅内遭暗杀身亡。15日下午斯里兰卡为卡迪尔加马尔举行国葬，斯总理拉贾帕克萨在讲话中呼吁国民搁置分歧和国际社会共同努力，铲除恐怖主义。

外电报道如下：Sri Lankans cremated their assassinated foreign minister Monday as the government urged the international community to clamp down on overseas supporters of Tamil rebels amid fears the killing could scuttle a three-year-old cease-fire.

句中的clamp down on表示"施压于；压制；限制；对……进行取缔"的意思。例如：The government is clamping down on teenage drinking.（政府正在禁止青少年饮酒。）Following the military coup, there has been a clampdown on press reporting in the capital.（军事政变以后，对首都的新闻报道进行压制。）