Weeks after xenophobic protests drove thousands of migrant workers from South Africa, rows of sewing machines stood idle at a clothing factory in Newcastle, a manufacturing hub in the eastern province of KwaZulu-Natal.

The campaign led by anti-immigrant group March and March sought to free up jobs for South Africans, a third of whom are unemployed. But local manufacturers have struggled to fill vacancies left by foreign workers.

Reuters visited three factories in late July whose owners said they had lost between 12% and 19% of their workforce during the protests. Some workers had sewing skills in short supply, the owners said, while few locals were willing to take the low-paying jobs.

"People don't want to work in factories," said Mpho Nkosi, a 29-year-old South African administrator at one of the firms.

Migrants typically work in sectors unappealing to locals, analysts say. It is unclear how widespread current labour shortages may be, but there have also been reports of unfilled jobs in sugarcane fields.