Oprah Winfrey is encouraging students at her new school in South Africa to take up free HIV tests and treatment.

The US television host took a test herself at the academy she set up to provide for poor families. The star commented: "Today I have taken the test to demonstrate why it's so important."

Although many of the youngsters at the school are known to come from families affected by Aids, Winfrey said no-one would be made to take a test.

The facility was officialy opened last week at a ceremony attended by celebrities including director Spike Lee, Tina Turner and former South African President Nelson Mandela.