Since 1992, more than 100 westerners have been kidnapped but none until this week has been killed. Usually, they are treated well and released after the Yemeni government makes promises of roads or schools or clinics for the kidnappers' communities.
On Monday, however, when 18 tribesmen held up a convoy with Kalashnikovs and bazookas, there was no public-spirited motive. The kidnappers were extremists who, according to Yemeni officials, demanded the release of two Islamic clerics arrested two weeks earlier in a crackdown on the vigilante enforcement of strict Islamic rules in southern Yemen.
One has not been named but the other is thought to be Saleh Haidara al- Atwi who is understood to command the support of other fundamentalist tribesmen in the region and is an admirer of Osama bin Laden, the man blamed by the United States for the bombing of its embassies in Kenya and Sudan last August.
According to Stuart Poole-Robb, chief executive of Merchant International Group (MIG), which advises multinational companies on security, alarm bells have been ringing over reports that supporters of Mr bin Laden met in Syria following the British and American bombing of Iraq.
"The fundamentalists are furious over the bombing of Iraq and a backlash is expected," he said. "The feeling in the intelligence community is that Bin Laden's supporters met to identify soft targets for attack. As well as places like Yemen, we can expect problems next year in Morocco, Egypt, Libya and elsewhere."
According to the Yemeni authorities, when the hostages' convoy of five vehicles was surrounded by the kidnappers there was an exchange of fire but no one was injured. However, Mr Poole-Robb's sources in Yemen say a number of police had been hit by gunfire. The holidaymakers were on a tour organised by Explore Worldwide.
"As a result, there was a certain desire for revenge," he said. "That, coupled with the fundamentalist element resulted in a tinderbox atmosphere waiting to ignite. The ambassador asked the Interior Minister not to use force, but the Yemenis went in in a gung-ho fashion. That was a mistake, as the deaths of the Britons testify." The Yemenis insisted the kidnappers began killing hostages before the rescue attempt.
The Foreign Office said that yesterday morning Victor Henderson, the British ambassador, met the Interior Minister, General Hussein Mohammed Arab and made clear that Britain wanted to see no military intervention.
"The ambassador especially made it clear that no violence should take place and that the safety of the hostages was paramount," said the spokesman. "He made it clear that no rescue attempt should be made that put the hostages' lives at risk. We would regard that as a very specific request."
However, Mr Henderson was forced to seek a second meeting with the minister when news of the rescue attempt was broken by Reuters news agency. It is not known how much detail of the attack was passed on to the ambassador.
It is possible the Yemeni authorities felt the need for decisive action because of the increasing number of such incidents. Three weeks ago other tribesmen kidnapped four German tourists. Yemeni newspapers said the abductors demanded a ransom of pounds 400,000, luxury cars, houses and state jobs for senior tribal members. On Boxing Day, other tribesmen blew up Yemen's main oilpipeline, which carries 150,000 barrels per day.
They are angry at levels of poverty in an oil-rich country and they have enough weaponry to cause chaos. Illicit guns are openly carried in Yemen. Estimates put the number of firearms at nearly 50 million - more than three times the population of 16 million.
The violent outcome is in contrast to other incidents where hostages were treated well. Last April, David Mitchell, a British Council worker in Aden, was kidnapped with his wife, Carolyn, and their son, Ben. They were released unharmed after 17 days and said they were treated well.
Giorgio Bonanomi, a 49-year-old Italian tourist who was kidnapped last year, said he enjoyed his five days as a prisoner enormously.
From now on, however, no one is likely to treat Yemeni kidnapping with such levity.
The Yemen: Facts and Figures
Population: 16 million
No. of firearms: 50 million
Capital: Sanaa. Aden declared economic capital when North and South Yemen merged in 1990.
Area: 536,869 sq km; bordered by Saudi Arabia, Oman, the Red Sea and the Indian Ocean.
Armed Forces: 42,000, with reserves of 40,000. The army has 37,000 men, the navy 1,500 and the air force 3,500.
Economy: One of the poorest Arab nations: per capita GDP of $280 a year. Unemployment about 35 per cent.
A small oil producer, Yemen pumps about 390,000 barrels a day. Up to 30 foreign oil companies operate in its main oil fields.Tourism generated $100m in 1997.
Politics: Turkey withdrew from North Yemen in 1918, and Britain from South Yemen in 1967. More than 100 kidnappings since 1992.