More than two thirds of South Africans believe that most problems in the country are caused by illegal immigrants, researchers said on Thursday.

Some 67 percent of South Africans believed this in 2006, as opposed to 47 percent in 2002, said Future Fact researcher Debbie Milne at a conference in Johannesburg.

Also, 39 percent of South Africans said they were seriously considering leaving the country in 2007, as opposed to 18 percent in 2000. The increase was up across all races.

"South Africa as a society has a number of unhappy people who feel helpless and hopeless about their future," said Milne.

However, she said South Africans were still "clearly seeking out commonality".

She said 53 percent of respondents said they considered themselves as South Africans, before identifying themselves by race or language.

Sapa