AMMAN, 29 October — A senior US diplomat was gunned down with three bullets to the chest outside his Amman home yesterday. Preliminary evidence recovered from the scene of the murder suggests the killer had a political motive, US officials said.

An unidentified assailant shot the official, named by diplomats as Lawrence (Larry) Foley, a senior administrator at the US Agency for International Development, USAID, at 7:30 a.m. (0530 GMT) as Foley was leaving for work, security officials said. No one immediately claimed responsibility for the murder.

The killing of the 62-year-old official came at a time of rising anti-American sentiment in the region amid US bias toward Israel and Washington’s threatened military campaign against Iraq.

A month ago the US Embassy in Jordan warned Americans of a report that a member of the Al-Qaeda network had plans to kidnap Americans in Jordan earlier this year.

A Jordanian security source said Foley was shot at close range before the assailant and possible accomplices fled the scene in an affluent area of the capital Amman.

"One assailant or more was behind the criminal shooting and investigations are continuing to reveal the culprits," the security official told Reuters.

Foley’s wife immediately notified security officials who rushed to the scene and cordoned off the area. A witness said Foley’s body was lying near his car in the garage of his two-story villa after the shooting.

"The body of the old man was lying there, with blood near the driver’s door of his Mercedes car that was parked in his indoor garage," he said.

Jordanian officials expressed shock and indignation at the assassination, the first killing of a Western diplomat in the security-conscious country.

"This attack, regardless of its motives, is an attack on the country and its national security," Petra state news agency quoted Information Minister Mohammad Adwan as saying.

Later Adwan told reporters that progress was being made by investigators in the case but it was premature to speculate about who was behind the killing.

"It’s an isolated incident...it’s very unfortunate that the American diplomat passed away. We are sure whoever has done it is targeting not only the US but Jordan also," Adwan added.

Jordanian Foreign Minister Marwan Muasher visited the US Embassy to express condolences and told Petra the authorities would act firmly and bring the culprits to justice soon.

The assassination was an affront to tough security measures in the kingdom, which have included arrests of scores of Iraqi nationals without residency status as part of contingency plans before a possible US assault on Iraq, officials privately say.

Security was tightened further at the US Embassy in the Abdoun district of the capital and at other Western embassies in the country, according to diplomats.

US Ambassador Edward Gnehm told a press conference in Amman later yesterday that the United States "will not rest" until those behind the murder of the American diplomat are found.

"We are working closely with the Jordanian authorities to apprehend the person or persons responsible for this crime and we will not rest until they are found," Gnehm said.

Saying "we are all simply devastated", Gnehm denounced the killing as a "heinous and cowardly act" and said that he had received a call of condolences from King Abdallah.

"We are outraged by this incomprehensible act. There can be no possible explanation for a heinous act of this kind.

"The cowardly criminal act that took away Larry’s life today took away something from within us all and we will not allow the life of such a great and peaceful man to be defiled by an act so evil, so cowardly."