Authorities in the U.S. state of Virginia have executed a Pakistani man convicted of killing two Central Intelligence Agency employees in 1993.
The U.S. State Department fears there could be retaliatory violence against U.S. targets worldwide.
Pakistani Mir Aimal Kasi was put to death by lethal injection Thursday night at the Greensville Correctional Center in Jarratt, Virginia.
Witnesses say Kasi whispered "There is no God but Allah," shortly before losing consciousness.
His execution comes nearly five years to the day after he was convicted for killing two CIA employees while they were driving outside the agency's headquarters in Langley, Virginia.
In his last interviews just hours before his execution, Kasi said it was wrong to kill civilians, but that he had no remorse for killing two agents of the U.S. government. He said he carried out his attack to protest U.S. policies toward Muslim countries.
After he killed the two CIA employees with an AK-47 machine gun, Kasi was able to fly out of the United States, despite traveling with an expired passport. He was arrested by U.S. agents four and half years later in his home country of Pakistan.
The FBI and the CIA never found evidence that he was linked to an organized terrorist organization, but extremist Islamic militants have hailed him as a hero.
The U.S. State Department has warned that Kasi's execution could result in retaliatory violence against Americans around the world.
A day after his conviction in 1997, four American oil executives were killed in Karachi, Pakistan, in apparent retaliation.