Eyele Godebo is surveying the wreckage of his livelihood. 'Fridge, money, clothes, shoes,' he says, 'everything has been taken.' He had built his small shop from nothing after migrating to South Africa to earn money for his Ethiopian family. Now he has nothing.

Godebo is not alone. In the past week, thousands of foreign citizens working in South African cities have been subjected to brutal attacks. Shops have been burned and looted. More than 5,000 people have been forced to leave their homes and at least six have been killed.

The perpetrators of all this violence are mobs of poor men, mostly from the Zulu ethnicity. With one in four South Africans unemployed, these mobs blame workers from other parts of Africa for 'stealing jobs'. Tensions have been building for some time, but these riots were sparked when the Zulu kingBefore South Africa was colonised by British and Dutch invaders, the Zulus were organised into one of the region's largest and most powerful political units, known as the 'Zulu kingdom' or 'Zulu empire'. Today the king has little political power, but still exerts influence among some Zulus. said that foreigners should 'go back to their countries'. A minority of his people took it up as a rallying cry.

South Africa has a large foreign population, with an estimated five million migrants in a population of just over 50 million. And it is true that some come in search of work: South Africa is far wealthierThe average income in South Africa is just over 7,000. This is not much by European standards, but it is enormous compared to some countries in the region. Zimbabwe, for instance, has an average income of little more than 300. than many of its neighbours. Yet many of the people who have been attacked are not economic migrants: they are refugees seeking to escape war and hardship in other African countries.

The South African president Jacob Zuma (himself from a Zulu background) condemned the attacks this weekend, saying that they 'go against everything we believe in'. But many criticised him for taking too long to respond; protesters of all ethnicities filled the streets of Durban and Johannesburg to demonstrate against xenophobiaLiterally 'fear of strangers' (in Greek), but the word is often used to refer to hatred or mistrust of foreigners as well as fear..

In other African countries, a bitter backlash has begun. The hashtag #xenophobicSA has attracted thousands of tweets and many have boycotted South African businesses abroad. In Mozambique, cars owned by South Africans were even pelted with stones.

To many people from countries all over the world, the situation may well seem depressingly familiar: when times get tough, people invariably turn on outsiders. From Nazi Germany to modern Europe, they say, the story only changes by degrees. At the slightest provocation, xenophobia rears its ugly head. Perhaps we have to face the uncomfortable truth that suspicion of foreigners is an innate human trait.

This is not about human nature, others respond: it is a social problem caused by material deprivation and inequality. The behaviour of these mobs is shocking, but they are responding to real hardships in their lives. Xenophobia is almost always a symptom of economic woes. Cure the underlying ill and people's 'natural' hatred of foreigners will disappear.