Neither team has been keen to talk to journalists in the run-up to the game
By Richard Fleming
BBC News, Benguela
The laid-back Angolan coastal city of Benguela has not slept well the past three nights, ever since discovering it was to host a semi-final match at the Africa Cup of Nations involving two of football's fiercest foes.
Reigning champions Egypt take on their North African rivals Algeria in a match which tournament organisers had hoped to avoid.
Pace of life in Benguela is usually sedate
Relations between the two countries have not been the best for many years, and were strained even further when violence marred a World Cup qualifier in Cairo last November.
Algerian players were injured after the team bus was attacked at the airport by local fans, triggering a number of unsavoury incidents in both Algiers and the Egyptian capital, Cairo.
This goes some way to explaining the frayed nerves which all sides have displayed in recent days.
Egypt have positioned the intimidating, no-nonsense Angolan police between themselves and the outside world.
Algeria beat Egypt in their World Cup play-off in November, sparking unrest
The Algerian team has been less surly, but clearly anxious ahead of the fixture.
They too have kept the media at arm's length, conscious of adding to an already tense situation ahead of the match with a misplaced comment.
Throughout all of this, fans from both sides have been arriving in the area amid tightened security.
There will be 600 officers on duty for the match, including 200 of Angola's elite force.
Benguela's police commander Simao Pereira de Sousa Ingles, told the BBC his city had never seen sporting event of such magnitude.
"It is classed as high risk, but we will keep the small amount of opposing fans well away from each other," he said.
Police in Angola have a reputation for over-zealousness, and if trouble flares they could become part of the problem rather than the solution.
For the earlier matches in Benguela, fans complained of being needlessly herded into small areas by mounted police, which only served to aggravate a previously good-natured crowd.
All matches so far at the Ombaka National Stadium have been heavily policed, and these police had at least two mobile water-cannons at their disposal.
Followers from both sides insist the match will pass off without incident, because the prize is not so great - a place in the final of the Africa Cup of Nations, as opposed to a berth at the first World Cup on the African continent.
The World Cup match sparked trouble in Algiers, Cairo and Paris
Anwar Abdrabou, the chief editor of the al-Ahram al-Riyadi sport journal in Cairo, said: "This match will be calm, between two Arabian brothers."
But this belies the recent tension between the two nations.
After initial spats between supporters late last year, Algeria beat Egypt in a World Cup play-off match, securing their place at the finals in South Africa.
Tension escalated and went beyond sport, with Libyan leader Muammar Gaddafi called upon to mediate in talks between the countries' two leaders.
Egyptian President Hosni Mubarak, in a televised address to the nation, insisted he would not tolerate the "humiliation" of Egyptian nationals abroad.
As Fifa opened an investigation into the attack on the Algerian team bus, the Egypt FA considered quitting international football for two years.
These incidents were not the first involving Egypt and Algeria.
Algerian star Lakhdar Belloumi was a key figure in a previous spat
A World Cup decider in Cairo in 1989 ended in violence, as Algeria's players were incensed at what they perceived to have been bias by the Tunisian referee.
Such was the level of anger that Egypt's team doctor lost an eye following an incident at a post-match reception.
Algerian player Lakhdar Belloumi was accused of the attack and an arrest warrant was only dropped by Interpol last April.
As for current players, Egyptian star Mohamed Zidan has referred to meetings with Algeria as "war".
It appears calls for calm have not been heard by everyone.