The American Civil Liberties Union (ACLU) and the Center for Constitutional Rights (CCR) have filed a lawsuit in Washington, D.C., demanding to know more about an alleged policy of assassinating Americans thought to be involved in terrorist activities.

"The United States cannot simply execute people, including its own citizens, anywhere in the world based on its own say-so," Vince Warren, Executive Director of the CCR, said in a media advisory. "The law prohibits the government from killing without trial or conviction other than in the face of an imminent threat that leaves no time for deliberation or due process. That the government adds people to kill lists after a bureaucratic process and leaves them on the lists for months at a time flies in the face of the Constitution and international law."

The groups have sued President Obama, the Central Intelligence Agency (CIA) and the Department of Defense.

"A program that authorizes killing U.S. citizens, without judicial oversight, due process or disclosed standards is unconstitutional, unlawful and un-American,” ACLU Executive Director Anthony Romero added in a prepared statement.

The suit was brought on behalf of Nasser al-Awlaki, father of Yemeni-American Muslim cleric Anwar al-Awlaki, who is targeted by the U.S. for assassination, according to the ACLU.

The US government in July said Awlaki was a key leader of Al-Qaeda in the Arabian Peninsula, placing him on its list of terrorism supporters, freezing his financial assets and banning any transactions with him.

Back in April a US official said President Barack Obama's administration had authorized the targeted killing of Awlaki, after American intelligence agencies concluded the cleric was directly involved in anti-US plots.

Awlaki, now based in Yemen, rose to prominence last year after he was linked a US army major who shot dead 13 people in Fort Hood, Texas, and to a Nigerian student accused of trying to blow up a Northwest Airlines flight on December 25.

"I am now afraid of what they will do with my son, he's not Osama Bin Laden, they want to make something out of him that he's not," his father told CNN in January.

The lawsuit cites government error in the detention and failed prosecutions of numerous terror war prisoners, many of whom never saw the inside of a courtroom or even heard the charges against them. The groups say this track record of grievous error does not inspire faith in the government's alleged policy of assassinations.

The groups are also demanding the government outline what criteria is followed to determine whether or not to murder someone.

"Disclosure of these basic legal determinations is the very essence of accountability, but the United States has so far failed to meet this requirement," noted Professor Philip Alston, who recently authored a report on extra-judicial assassinations [PDF link] for the United Nations Human Rights Council.

"Instead, it has claimed a broad and novel theory that there is a 'law of 9/11' that enables it to legally use force in the territory of other States as part of its inherent right to self-defence on the basis that it is in an armed conflict with al-Qaeda, the Taliban and undefined 'associated forces'. This expansive and open-ended interpretation of the right to self-defence threatens to destroy the prohibition on the use of armed force contained in the UN Charter, which is essential to the international rule of law.

"If other states were to claim the broad-based authority that the United States does, to kill people anywhere, anytime, the result would be chaos."

The Obama administration, CIA and Defense Department had not commented on the suit at time of this story's publication.

With AFP.