(BNA): The U.S. and British embassies in Kabul said on Monday the insurgent Taliban may have committed war crimes in southern Afghanistan by carrying out revenge murders of civilians, a charge denied by the insurgents. The U.S. Embassy in the capital Kabul tweeted a statement accusing the Taliban of killing dozens of civilians in the area of Spin Boldak in southern Kandahar province. The statement was also tweeted by the British embassy. “These murders could constitute war crimes; they must be investigated & those Taliban fighters or commanders responsible held accountable,” the U.S. Embassy tweeted. In a second tweet, it said: “The Taliban’s leadership must be held responsible for the crimes of their fighters. If you cannot control your fighters now, you have no business in governance later.” The tweets, accompanied by calls for a ceasefire, stepped up the United States’ public criticism of the group as U.S. troops withdraw and the Taliban goes on the offensive. U.S. Secretary of State Antony Blinken said last week that Afghanistan would become a ‘pariah state’ if any future Taliban rule in Afghanistan resulted in atrocities against civilians. The insurgents gained control last month of the strategic area of Spin Boldak, which lies at crossing with Pakistan, and heavy fighting has taken place since as Afghan forces try to recapture the area.