The guardsmen from the border post near Sendes, in the south of Tunisia, had even invited an Algerian civilian to join them in their evening meal; he too was dragged off and had his throat cut after armed Algerian fundamentalists suddenly set upon them. The dying guardsman told the authorities how they were tied up, their weapons and food seized, and then butchered before the terrorists fled back across the border.
The reaction of Tunisians to this attack, and a second one a day later in the Ain Draham region in the north, has so far been nothing but appalling silence.
These are the first attacks here since the start of the Algerian civil war three years ago. Some analysts speculate the raids were isolated and random acts by terrorists desperate for arms, but a more sinister interpretation, offered by Tunisian Islamic sources, among others, is that the strikes represent a new strategy of deliberately involving Tunisia because of its support for the Algerian government.
Whatever the truth, there is no doubting its anti-Islamic fervour as it strives to protect itself from the rising tide of Islam. Tunis, which recently hosted a regional meeting on co-ordinating ways of combating Islamic terrorism, is now deporting almost all foreign workers (especially Algerians) as security risks, as well as banning its local Islamic Party Ennahda, and jailing up to 8,000 of its members and supporters, according to human rights sources.
None the less, Islamic sources in Tunis say a number of young Tunisian fundamentalists are slipping across the Algerian border to join their comrades in the mountains.
Tunisia's silence, and its strenuous efforts to promote its image as a safe and friendly country - it successfully hushed up the highly mysterious death of a German woman tourist at the resort of Hammamet around Christmas - are aided by total government control of the press and the expulsion of critical foreign correspondents. The country's booming tourist industry is by far its biggest foreign currency earner, bringing in around US$2.5bn annually.
Egypt's tourist industry has already collapsed because of fundamentalist attacks, while a single incident in Morocco last year, in which two Spanish tourists were shot dead in a Marrakesh hotel, apparently by Algerian fundamentalists, has seen tourism drop by around 20 per cent.
The recent Algerian attacks inside Tunisia, and the authority's mounting concern about the domestic impact of the Algerian turmoil, are mirrored by a dizzying escalation of killings in Algeria itself during the traditionally peaceful month of Ramadan - now in its third week.
Even for a country numbed by a death toll now estimated at over 30,000, and where up to 800 people are said to be dying every week, the roll call in the past week's wave of terror has been horrifying. Each day, sometimes each hour, brings news of yet more killings, victims chillingly targeted for their "symbolic" secular profiles. Last week alone, a dozen of Algeria's best loved and renowned personalities - leading politicians, intellectuals, artists, teachers and journalists - were assassinated.
They include the director of the Algerian National Theatre, Azeddine Medjoubi, who was assassinated last Monday as he left the theatre just after lunch; on the same day the president of a student's union in Algiers, Abdelhafid Said, was gunned down; also killed was the director of a college in an Algiers suburb, Hocine Leklou, and an official from the Foreign Ministry Bachir Bentayeb; and, two days later one of Algeria's most famous singers, Rachid Baba-Ahmed,was assassinated in the western city of Oran.
While at the other end of the country, in Tizi Ouzou, capital of Kabylie, the renowned feminist leader Nabila Diahnine was shot dead with a hunting rifle. Then on Friday, Djamel Ziater, a leading regional journalist, was shot as he visited his mother's grave; he is the fifth reporter to be killed this month.