A US judge late Friday tossed a lawsuit against the Obama administration brought by survivors of three Americans killed by drone strikes in Yemen more than two years ago.

US District Judge Rosemary Collyer, siding with the administration, ruled that allowing the case to proceed "would impermissibly draw the court into the heart of executive and military planning deliberation" (PDF).

The suit (PDF), which was being handled by the American Civil Liberties Union and the Center for Constitutional Rights, exposed the administration's unmanned "targeted killing" program. The groups maintain thousands have been killed across the glove by US-backed unmanned drones.

The first-of-its-kind lawsuit alleged violations of international human rights and the US Constitution, arguing that "lethal force is a last resort to protect against a concrete, specific, and imminent threat of death or serious bodily injury."

The case was brought by the survivors of Anwar-Awlaki, a New Mexico native and radical cleric who the authorities said was an al-Qaida recruiter along the Arabian Peninsula and was associated with the September 11 hijackers.

Also killed in the 2011 Yemen bombings and named in the suit include Awlaki's 16-year-old son, Abdulrahman, and Samir Khan, who was editor of the English-language al-Qaida publication Inspire.

"The court's view that it cannot provide a remedy for extrajudicial killings when the government claims to be at war, even far from any battlefield, is profoundly at odds with the Constitution," Hina Shamsi, director of the ACLU's National Security Project, said in an e-mail. "It is precisely when individual liberties are under such grave threat that we need the courts to act to defend them. In holding that violations of U.S. citizens' right to life cannot be heard in a federal courtroom, the court abdicated its constitutional role."

Neither the boy nor Khan were intended targets.