A US peace activist interrupted a top White House aide today as he delivered a speech in Washington that sought to justify the government's drone assassination programme.
The Code Pink campaigner stood up and warned that the illegal killings endanger US national security by "creating more enemies."
John Brennan (pictured), US President Barack Obama's top counterterrorism adviser, had said that the "targeted strikes against specific al-Qaida terrorists prevent terrorist attacks."
Mr Brennan told the Woodrow Wilson International Centre for Scholars: "It is hard to imagine a tool that can better minimise the risk to civilians than remotely-piloted aircraft."
Mr Brennan was struck dumb when activist Medea Benjamin suddenly stood up and asked the audience of policy wonks: "Why are you lying to the American people and not saying how many innocents have been killed?"
The London-based Bureau of Investigative Journalism estimates that at least 392 civilians have been killed in the remote-controlled air strikes since 2004, including 175 children.
"Every time we kill somebody with a drone, we create more enemies," Ms Benjamin warned. "It just perpetuates the cycle of violence."
Police eventually hauled her out of the hall.
The American Civil Liberties Union (ACLU) is currently engaged in a legal battle to force the Obama administration to disclose more information about the assassination programme.
ACLU lawyer Jameel Jaffer challenged the US government to disclose "the memo that authorises the extrajudicial killing of American terrorism suspects" and "the evidence it relied on to conclude that an American citizen, Anwar al-Awlaki, could be killed without charge, trial, or judicial process of any kind."