The dead Britons - the mine manager and a mining engineer - and the geologist who was taken hostage have not yet been named by the Foreign office. A spokesman for the Canadian mining company Diamond-Works Ltd said relatives would have to be informed first. The other men who died in the attack were a Portuguese security officer and two Angolans.
A statement from the mining company said a gang of about 50 armed men had staged a hit-and-run assault on its Yetwene diamond mine in the north- east of the country at about 4am local time - 3am London time - on Sunday.
Workers at the mine live on the site, which is guarded by armed security staff. In the shoot-out with the attackers, believed to be from the rebel army Unita, five people were killed and 18 were wounded. Five more - two Filipinos, a South African, an Angolan with South African residency and the British man - are believed to have been taken hostage. A sixth man is unaccounted for.
A spokesman for the company, Michael Grunberg, said the remaining 13 expatriate staff were unharmed and had been flown to the capital, Luanda. "It is very rare in Angola for people to be taken captive," he said. "We have been here for four years and have never had an incident like this. This has taken everybody by surprise. We have two security companies at the site - they are both Angolan companies with expatriate training and have to be certified to a specific standard. Over four years, this is the first time a shot has been fired in anger.
"Our security contractors tried to repel them - but the attackers were firing wildly and randomly - they pressed the trigger and sprayed."
In 1996, the company, which has five concessions in Angola and two operating mines, employed the London-based military consultants, Sandline International, to provide advice on security. Sandline received widespread publicity during the "arms to Africa" affair earlier this year.
The identity of the attackers is not yet certain but witness accounts indicate that some were wearing clothing identified with the rebel army of Unita, and local military and police units.
Initial reports from the mine indicate there was some theft and minor damage to the company's vehicles and communication systems. Items such as food and radios were stolen during the attack but no diamonds were taken and stocks have since been removed.
DiamondWorks said in a statement that it deeply regretted the loss of life and called on the international community to condemn "this shameful act of violence".
It added: "The company will take all necessary steps to ensure that the missing expatriate personnel are safely returned to their homes and families as quickly as possible."
DiamondWorks' chief executive, Bruce Walsham, plans to fly to Angola from the company's London offices to help to secure the hostages' release.
Angola's MPLA government fought a two-decade-long war against Unita, which ended with the signing of peace accords four years ago.Reuse content