LONDON, AUG. 12 -- A British man shot dead by Iraqi soldiers while trying to flee across the Kuwaiti border to Saudi Arabia has become the first known Western casualty in the Persian Gulf crisis, the Foreign Office reported today.

Officials here said they believed the man, identified as Douglas Croskery of northeastern England, had been shot three times by an Iraqi patrol Saturday evening.

The shooting, combined with dramatic eyewitness accounts of Britons who fled Iraqi-occupied Kuwait over the weekend, is certain to increase popular patriotic fervor here. Many Britons, while supporting their government's hard-line response to Iraq's invasion of Kuwait, until now have reacted with little passion to the crisis and had viewed the gathering concern in the United States with sympathetic bemusement.

Britain was the first country to commit warplanes and naval ships to the U.S.-led force supporting Saudi Arabia. The television here showed crews of those jets and ships bound for the gulf this weekend while wives stood aside teary-eyed.

There are more than 4,500 Britons in Kuwait and Iraq, and the Foreign Office has advised them to stay put for their own safety. But after first attempting to play down the seriousness of their situation, British officials in recent days have begun referring to them as "prisoners" and "hostages." Britain has sought to mount an international diplomatic effort with help from other European Community states and from the Soviet Union to press Baghdad into allowing their release.

Croskery, who worked for an international printing company, was traveling in a convoy of two or three cars heading for the border with Saudi Arabia when soldiers stopped the second car and opened fire, according to the Kuwaiti ambassador to Britain, Ghazi Rayes, who said he had received a report on the incident.

"They asked the others to leave the car and go walking to the border, which was about five kilometers {three miles}, in the heat," Rayes told Sky News here. "They dragged the injured man out of the car, threw him on the ground and left him bleeding there."

The Foreign Office spokesman said, "This tragic death is a direct result of the Iraqi occupation of Kuwait. It must end." He said a strong protest was delivered to Iraq, which was reminded that it is responsible as an occupying power under the Fourth Geneva Convention for the protection of all civilians in Kuwait, domestic and foreign.

The death "must be construed as murder," the spokesman added.

William Waldegrave, Britain's deputy foreign minister, told a press conference:

"This shows yet again that the situation is extremely dangerous and it shows that the Iraqis are continuing to behave in a ruthless and barbarous way. But I think the most important thing to say to the British people, whose stalwart attitude is so impressive so far, is that this very dangerous situation will not be resolved without potential tragedy and without the need for very steady nerves here in Britain."

Some of those who had escaped Kuwait over the weekend arrived today at Gatwick airport and told how they had weaved their way through the desert to the border after dark with the help of Kuwaiti guides.

Adrian King, with his pregnant wife Anne and 2-year-old son, said they decided to flee Kuwait after a German neighbor was raped by an Iraqi soldier. "The soldier had tied the husband up, raped his wife and then made them sit down and have a cup of tea," Anne King said.

The Kings heard a short burst of machine-gun fire as their convoy of cars neared the border but said they were not stopped. "The main problem was the Iraqi troops that we passed as we went along the way -- there were a lot of them around," said Adrian King. "We were absolutely sure we would be picked up. In fact, on one occasion we were going so fast that I believe we caused one tank to go into another tank.

"As we got to the border, the Iraqis stopped one car that wasn't with our convoy, there was a short burst of machine-gun fire obviously to warn them to stop, but we decided to make a quick dash for it."