The BBC's Khalid Javed: "Foreigners as negotiating pawns"

Western hostages are valuable negotiating tools for tribes demanding improved infrastructure and social services, such as new roads and electricity. The kidnappings also bring international attention to Yemen.

But until now the kidnap gangs were renowned for treating their captives like honoured guests, explaining that their argument is with their own government and not the hostage. Nearly all previous hostages had been well treated and released unharmed.

Often, releases were secured with government promises of cash or luxury gifts, such as cars to tribal leaders.

But last August President Ali Abdullah Saleh introduced the death penalty for kidnapping. It is not clear whether the shoot-out that ended the latest incident was unplanned or part of a new get-tough policy.

The BBC's Barnaby Mason looks at the history of a country only recently united after civil war

The BBC's diplomatic correspondent Barnaby Mason said that Islamic groups helped the North win the 1994 civil war, but their later reported activities - like running military training camps and trying to enforce a strict Islamic code of behaviour - have been less welcome to the government.

Historic temples

Yemen remains the poorest country in Arabia and its economic situation has deteriorated with the collapse of oil prices.

President Ali Abdullah Saleh: Kidnaps concern his government

Tourism is seen as one way of earning much needed extra income in a country where the annual income per head is less than £300.

Although the repeated kidnappings, and the publicity that comes with them, are a concern to the Yemeni Government, more and more people are travelling to Yemen.

In 1997 there were 84,000 foreign tourists - a 10,000 increase on the number of visitors in 1996.

Among the tourist attractions are temples, engravings and statues dating from the first kingdom of Sheba in the 10th Century BC. Tourists can also enjoy near-deserted Red Sea beaches and spectacular mountain scenery.

Saudi expulsions

The Yemen economy is still trying to recover from the massive blow when Saudi Arabia expelled 850,000 Yemeni workers in 1990 because it felt Yemen was too friendly with Iraq.

The BBC's Frank Gardner: "Yemen's a place to discover but not to relax"

Relations with Saudi Arabia are still tense.

In the north of Yemen, tribesmen attacked the country's main pipeline 19 times last year.

They are demanding a percentage of the profits from oil pumped on their land, the building of power plants and a water distribution system.

After similar attacks earlier in the year the Yemeni Government accused Saudi Arabia of inciting the violence.

Until recent years, Yemen was subject to civil war between north and south, between the forces of President Ali Abdullah Saleh and his southern rival, Vice-President Ali Salem al-Baidh.

In 1991 the two sides agreed to merge but fighting broke out again in 1994 after which northern politicians based in Sanaa establish control over the southern capital Aden.

Past kidnappings

Among the Britons who have been kidnapped in Yemen are English teacher David Mitchell, his wife Carolyn and their teenage son Ben.

The Mitchell family: Held for two weeks

The family, from Sidley, East Sussex, were snatched in April this year as they were on their way to catch a flight home after an Easter holiday. They were held to ransom and released a month later.