South African troops, acting under the auspices of the Southern African Development Community (SADC), entered neighbouring Lesotho before dawn yesterday to "restore stability" to the tiny, troubled kingdom.
But the intervention, undertaken in response to a request from the Prime Minister of Lesotho, Mr Pakalitha Mosisili, ran into fierce resistance from soldiers of the Lesotho Defence Force and aroused the wrath of supporters of the three main opposition parties.
Before night fell at least five South African soldiers had been killed and nine wounded during the drive to capture strategic centres in and around the capital, Maseru. Several South African-owned shops had been set alight by opposition supporters.
The 600 South African soldiers were due to be reinforced by 200 from Botswana, who spent most of yesterday travelling hundreds of kilometres overland to Lesotho under the terms of an SADC agreement for a joint task force.
Lesotho - a mountainous enclave entirely surrounded by South Africa, is one of the poorest countries in the world and a major recipient of Irish aid.
The general election in May was won decisively by Mr Mosisili's Lesotho Congress for Democracy. But the three opposition parties - which won only one seat between them - charged that the poll had been rigged and mounted a continuous protest outside the palace of King Letsie III.
By mid-September opposition supporters had taken control of the streets of Maseru: they hijacked government vehicles and impounded them in the grounds of the palace; blockaded the entrances to the National Assembly to prevent parliamentarians from sitting; and barricaded the streets to keep civil servants out of their offices.
Maseru became ungovernable, largely because a mutiny in the Defence Force purged it of more than 20 senior officers, including the commander, and left junior - and pro-opposition - officers in control.
It was in these circumstances that the Prime Minister, Mr Mosisili, wrote to the heads of states in South Africa, Botswana, Lesotho and Mozambique - all members of SADC - requesting military intervention.
Speaking in the South African Parliament yesterday, the acting President, Chief Mangosotho Buthelezi, said: "The aim of intervention is to restore stability as soon and as quickly as possible and to withdraw . . . as soon as that has been achieved."
The orders for the incursion were signed by Chief Buthelezi as Acting President. But he was acting with the full knowledge and consent of President Nelson Mandela and the Deputy President, Mr Thabo Mbeki, neither of whom was in South Africa yesterday.
Contingency planning began a week ago.
Yesterday's military intervention was preceded by an attempt by a three-member SADC delegation to secure a political settlement between Lesotho's ruling party and the three opposition parties.
The attitude of King Letsie, a constitutional monarch, remained unclear. A spokesman for the royal family was quoted on South African radio as condemning the "invasion" as an affront to Lesotho's sovereignty.