The violence that has erupted in poor neighbourhoods in the south of Buenos Aires in recent days has shocked many in Argentina.
But for others, it was a conflict waiting to happen.
The clashes started last week when several hundred families moved on to a patch of open land in the rundown neighbourhood of Villa Soldati in the south of the capital.
They were challenged by the existing residents and violent clashes broke out. The police, at first, were noticeable by their absence.
At least three people were killed, two Bolivian men and a Paraguayan woman. The Bolivian community says a fourth person was killed but the authorities have not confirmed this.
Stung by criticism that it was slow to respond, the government of President Cristina Fernandez de Kirchner sent in heavily armed officers, backed by armoured vehicles and helicopters, to restore order. She also set up a new security ministry.
A tense calm was imposed but more homeless families have been taking over unoccupied plots, disused factory grounds, a football pitch and municipal land.
The neighbours, disturbed by the loss of scant open space as the long school summer holidays began, responded. Riot police have been moving from site to site to try to restore and maintain calm.
The clashes have provoked insults and accusations between the national and Buenos Aires city governments, while the rest of the Argentine population is nervously watching to see whether these are isolated incidents which the authorities can contain or the beginning of something much bigger and more serious.
Gendarmerie officers stand guard at a land occupied by squatters in Villa Soldati neighbourhood, Buenos Aires, Argentina on 11 December, 2010 Order was restored after the weekend’s violence but occupations are continuing
The national government accused the Buenos Aires city mayor, Mauricio Macri, of stirring up xenophobia with his call for immigration to Argentina to be controlled.
Others have accused the former president, Eduardo Duhalde, of being behind moves to cause unrest in the run-up to next year’s presidential election.
Extreme right-wing nationalist groups have posted inflammatory comments on their websites and known football hooligans, the barra brava who often have links with local political groups, have been photographed in the thick of the action. Some reports say that criminal gangs involved in the illegal sale of land provoked the disturbances.
All of these hypotheses are still being investigated and it is possible that they all played some part in creating the conditions that led to the conflict.
But it is also likely that the simplest explanation is the most credible. There are many homeless people in Buenos Aires who will go wherever they must to build a home. And often the locals simply resent seeing their sparse open spaces disappearing.
One woman was quoted in a national newspaper as saying: “We’re poor as well. But we pay our rent and nobody gives us anything.”
The population of Buenos Aires’ shanty towns, or villas, has grown by 25% in the past two years, reports say. Up to 200,000 people, or 7% of the city’s population, now live in 14 such settlements in and around the capital.
Many of them are from neighbouring Bolivia and Paraguay, as well as Peru and Argentina’s poor northern provinces. The men often work in construction and the women as domestic workers. Or they are employed in poorly regulated factories or sell whatever they can on the street.
A boy sleeps at a makeshift shelter in a property alongside a closed slaughterhouse after it was occupied by squatters, on the outskirts of Buenos Aires, Argentina, 14 December 2010. The unrest has highlighted deep-seated social problems
Bolivian President Evo Morales appealed to his compatriots not to continue the illegal occupations and said that if they wanted land they should return home. The Argentine Foreign Minister, Hector Timerman, has met his Bolivian counterpart to discuss the issue.
The disturbances were all in the industrial area to the south of Buenos Aires, a bleak region which most Argentines rarely, if ever, visit. The authorities have also been accused of manipulating official statistics on poverty which portray the country as in better shape than it really is.
So the ferocity of the violence, the extent of the poverty and the desperation of both the immigrants and the existing residents have taken many in Argentina by surprise. The national media have been full of comment, analysis and debate on the events in Villa Soldati.
Anthropologist Cristina Cravino, writing in one Sunday newspaper, said the region where the disturbances have been taking place has been characterised for decades by the absence of the state. The residents, she added, simply have no option: if they want to build a home, they must move into a shanty town.
While the summer heat and a clash over a plot of land may have sparked the violence, it is becoming clear that Argentina faces a number of fundamental problems relating to poverty, immigration and land distribution which will not be easily solved.