Neighbors and friends of a U.S. diplomat gunned down outside his home Monday were shocked and concerned about their own safety.

The U.S. Embassy warned Americans in Jordan, known for its usually tight security, to "remain vigilant" after a gunman shot and killed Laurence Foley, who worked at the U.S. Agency for International Development.

"All of us in the American community convey our deepest condolences to Foley's family on the death of such warm and loving man," the Embassy said in a statement. "We are outraged by this incomprehensible act."

Neighbors watching from their front gates as U.S. and Jordanian security officials searched for evidence outside Foley's home, said they had not heard or seen anything until police cars arrived, sirens blaring.

"We are all sad for his killing because he and his wife were a nice couple and everybody liked them in the neighborhood," said one veiled woman, who gave her name only as Um-Ayman.

Another Jordanian neighbor, Um-Saeed Sbeih, said Foley and his wife would walk their dog every day and always wave and greet them in Arabic.

"It is a hideous crime, who ever did it should be punished," she said. "Why should ordinary people get killed and punished for the crimes of their leaders? We like the American people and we were happy to have this man as a neighbor."

It was the second time a foreigner was killed in more than a year in the Rawabi neighborhood.

An Israeli diamond merchant, Yitzhak Snir, was shot outside his home in August 2001. No one has been arrested, but Jordanian officials have suggested Snir was killed in a business dispute.

Expatriates living in Jordan said they were concerned about their safety.

"People should be worried and more careful," said Lisa Khoury, 44, from Dallas, Texas, who knew Foley.

But Khoury, who works for a charitable organization and is married to a Jordanian, said she would not consider leaving. "Americans who are here like Jordan. Otherwise they won't be here."