(CBS) Neither Virginia's governor nor the highest court in the nation stopped the execution of Aimal Khan Kasi, the Pakistani militant who killed two CIA workers in 1993. Kasi, 38, died by lethal injections shortly after 9 p.m. in Virginia.

"There is no God but Allah," Kasi said, softly chanting in his native tongue until he lost consciousness.

Hours before the execution, the U.S. Supreme Court rejected an appeal and Gov. Mark R. Warner denied a request for clemency, saying Kasi has "shown absolutely no remorse for his actions."

Kasi killed CIA communications worker Frank Darling, 28, and CIA analyst and physician Lansing Bennett, 66, as they sat in their cars at a stoplight in McLean. Three other men — an engineer, an AT&T employee and a CIA analyst — were wounded as Kasi walked along a row of stopped cars, shooting into them with a semiautomatic AK-47 rifle.

He fled the country and spent most of the next 41/2 years hiding in and around the city of Kandahar in southern Afghanistan. He was caught in a hotel while visiting Pakistan and was returned to the United States.

Kasi confessed to the slayings during the return flight, saying he was angry over CIA meddling in Muslim nations.

Kasi's pending execution prompted protests in Pakistan. U.S. authorities, who say they have heard increased "chatter" about new terror attacks feared that the execution might prompt an incident, reports CBS News Correspondent Bob Orr. The FBI alerted hospitals in Washington, Chicago, San Francisco and Houston that they could be targeted by terrorists between December and April.

However, as Orr reports, the problem remains that all of the threats lack specifics. No precise time, date, or place.

Security around Greensville was greatly increased, according to a prison source, but the only evidence was two correctional officers with shotguns standing on each side of the road near the prison entrance, and several officers with sidearms in front of the prison.

Kasi spent the day in a cell only a few feet — from Virginia's death chamber. He met with two of his brothers, his attorneys and his spiritual adviser, corrections spokesman Larry Traylor said. No family members of the victims attended the execution.

Charles R. Burke, one of Kasi's defense attorneys, declined to say what the funeral arrangements were or when the body would be claimed. Kasi's family said he would be buried next to his father in a graveyard of fellow tribesman near his hometown of Quetta.

Kasi was convicted in November 1997 as Mir Aimal Kasi, but he said that name is erroneous because of a misprint on his visa.

Some Pakistani politicians pleaded with American officials to spare Kasi's life, saying commutation could "win the hearts of millions" and help the United States in its war on terrorism. Hundreds of religious students protested in Pakistan this week, warning Americans there that they will not be safe if Kasi was executed.

Last week, the State Department warned that Kasi's execution could lead to acts of vengeance against Americans everywhere. Two days after his conviction, assailants shot and killed four American oil company workers in Karachi, Pakistan.

Kasi told The Associated Press in an interview last week that he had no regrets about the killings but did not want any retaliation for his execution. Kasi's family near Quetta, Pakistan, also pleaded for calm.

"Kasis are a peaceful tribe. We want peaceful solutions to every problem," said his older brother, Nasibullah Kasi. "We do not want the Kasi name to be used to harm anybody."

The family of Judy Becker-Darling, widow of Frank Darling, also hoped for calm.

"We will spend time in prayer for Kasi, that God will have mercy on his soul, for his family, that there be no terrorism reprisal, and for world peace," the family said in a statement.

CIA Director George J. Tenet said in a statement that "our thoughts" are with the victims of the shooting. "They and their loved ones will always be a part of our agency family," he said.

State Police and other agencies increased security in northern Virginia and around Richmond's Capitol Square.

"Someone with national and even international credentials like this, it mandates that we take extra precautions," said Col. Gerald Massengill, head of the Virginia State Police.