Harare - Attacks on immigrants living in South Africa dominated a regional summit in Zimbabwe on Wednesday, with President Robert Mugabe criticising workers who seek new lives in Johannesburg and other South African cities.The Southern African Development Community (SADC) meeting was meant to discuss industrial growth, but attention focused on recent xenophobic violence in Johannesburg and Durban in which at least seven people have been killed.Thousands of immigrants in South Africa were displaced by the unrest this month as local mobs targeted workers from countries such as Zimbabwe, Mozambique and Malawi.The presidents of all three of those countries - and South Africa's President Jacob Zuma - were among the 10 heads of state at the one-day event in Harare.'Heaven on earth'"Long ago, going to South Africa was like going to heaven on earth," Mugabe told reporters after the summit."The majority of our people go to work on farms. Then they run away from farms to start new lives in the cities. But why do that? People must get back to their own countries."Our people should not have the instinct of rushing into South Africa."Mugabe said Zuma had briefed delegates on the attacks and measures taken to prevent them reoccurring."What we can do in the circumstances is not just to criticise but also to assist the government and people of South Africa," Mugabe said, striking a conciliatorily note after weeks of fractious regional relations.'Root causes'Zuma, who condemned the attacks after an outcry at home and abroad, this week risked stoking tensions further by questioning why migrants elsewhere in Africa felt they had to flee their own countries.The subject of the summit - industrialisation - itself raised the issue of why so many citizens of neighbouring countries head for South Africa, the continent's most sophisticated economy.Mugabe has been widely blamed for a collapse in Zimbabwe's economy which has sent millions of his people to seek work in South Africa.In Johannesburg, Graca Machel, the widow of late anti-apartheid hero Nelson Mandela, described the unrest as "a wake-up call to the whole of South Africa and to the whole of SADC."Machel spoke at a memorial service for a Mozambican migrant murdered in an attack that was dramatically captured on camera."Until we address the root causes of all these problems... we shouldn't be surprised if other eruptions of this kind of thing happen," she said.The Harare meeting was a follow-up to a summit in Victoria Falls last August which resolved to discourage the export of primary goods and develop industries to ensure southern Africa reaps maximum benefit from its resources."Despite the rich endowment of our natural resources, about 70% of our people live below the poverty line," Mugabe said, calling for the region to develop its own industries rather than exporting raw materials.Many member countries of SADC, which seeks to promote economic, political and security cooperation, are rich in minerals.