Rights groups challenge Obama on targeted killings

President Barack Obama delivers remarks to military personnel at Pensacola Naval Air Station in Pensacola, Florida, June 15, 2010.

WASHINGTON (Reuters) - Civil liberties groups sued the Obama administration on Monday over a program they said illegally tries to kill U.S. citizens believed to be militants living abroad, like the anti-American cleric Anwar al-Awlaki.

The American Civil Liberties Union and the Center for Constitutional Rights filed a lawsuit on behalf of Nasser al-Awlaki, the father of the Muslim cleric, arguing targeted killings violate the U.S. Constitution and international law.

U.S. authorities have tied the cleric to the failed bombing attempt of a U.S. commercial jet on Christmas Day in 2009 and to an Army major who went on a shooting spree that killed 13 people last year at Fort Hood in Texas.

No charges have been publicly filed against al-Awlaki, who was born in the United States but left in late 2001. He is believed to be in Yemen, where al Qaeda has been growing.

"A program that authorizes killing U.S. citizens, without judicial oversight, due process or disclosed standards is unconstitutional, unlawful and un-American," Anthony Romero, executive director of the ACLU, said in a statement.

President Barack Obama's National Security Council gave the Central Intelligence Agency the green light earlier this year to kill al-Awlaki, officials have said.

White House officials have also said Americans who fight alongside groups like al Qaeda are "legitimate targets" for lethal strikes.

The Obama administration declined to comment specifically about the lawsuit filed by the two group, but said the government has the right to use force to defend the country and to defeat al Qaeda.

"The U.S. is careful to ensure that all its operations used to prosecute the armed conflict against those forces, including lethal operations, comply with all applicable laws, including the laws of war," said Justice Department spokesman Matthew Miller.

"This administration is using every legal measure available to defeat al Qaeda, and we will continue to do so as long as its forces pose a threat to this nation," he said.

The civil liberties groups argued that Americans accused of wrongdoing should be tried in court under the Constitution and could be targeted for killing only if there were an imminent threat from a person and there were no other ways to stop it.

The groups said the people being targeted are far from any battlefield like in Iraq or Afghanistan, which they said undermines the administration's justification.

They asked for a federal judge to issue an injunction preventing the Obama administration from killing al-Awlaki and forcing it to publicly reveal the criteria for determining who can be targeted.

CIA spokesman George Little said: "This agency acts in strict accord with American law." Representatives of the Defense Department had no immediate comment.

(Reporting by Jeremy Pelofsky; Editing by John O'Callaghan and Jackie Frank)