The family members argue that the US government’s killing of the three men “violated fundamental rights afforded to all US citizens, including the right not to be deprived of life without due process of law.”

The suit was filed Wednesday on behalf of Awlaqi and Samir Khan, killed in a drone strike on September 30, 2011, and Awlaqi’s 16-year-old son Abdulrahman, killed in a similar strike two weeks later.

The four defendants named in the suit, filed in a US district court in the capital, are Defense Secretary Leon Panetta, CIA Director David Petraeus and two special operations commanders believed to have authorized the strikes.

The family members, who joined with the American Civil Liberties Union to file the suit, claim the killing of Awlaqi was unjustified because he posed no imminent threat and because the United States was not at war with Yemen.

The lawsuit cites media reports that Khan and the younger Awlaqi were not the intended targets of the strikes that killed them, accusing the US military of having failed to take measures to prevent harm to civilians.

The plaintiffs do not specify the amount of compensation they are seeking, saying it should be determined at trial.

US President Barack Obama defended the killing of the elder Awlaqi, saying he was actively plotting deadly attacks against Americans as head of external operations for Al-Qaeda in the Arabian Peninsula (AQAP).

The Yemen-based group is currently believed to be the global network’s most effective and lethal franchise, and Awlaqi — a charismatic preacher fluent in Arabic and English — was seen as a particularly effective global recruiter.

US officials believe Awlaqi played a significant role in the attempt to bring down a US airliner over Detroit by an assailant with explosives sewn into his underwear on December 25, 2009.

He was also believed to have coordinated the thwarted 2010 plot to blow up cargo aircraft bound for the United States and had called for attacks against US and Arab governments.

In 2010 a US judge dismissed a lawsuit filed by Awlaqi’s father Nasser — the main plaintiff in the latest suit — which had sought to block the United States from targeting Awlaqi for assassination.

The judge in that case said the targeting of Awlaqi raised a number of thorny legal questions but said the courts were not equipped to make real-time assessments of emerging national security threats. AFP