South African authorities detained a 15-year-old girl who was traveling to join Islamic State, the state security ministry said on Monday, the country's first known arrest linked to the militant group.
The ministry said it was investigating whether Islamic State had a recruitment network in South Africa.
The teenager was stopped at Cape Town airport on Sunday after evidence was found in her bedroom indicating she had been in contact with Islamic State recruiters, the ministry said.
"We can confirm that she was planning to leave the country with the intention of joining IS, and had been actively engaged with social media networks," Minister of State Security David Mahlobo was quoted as saying in The Star newspaper.
"An investigation is under way as to how far this network goes, whether there is a cell in the country. We cannot allow South Africa to be used as recruitment space," he said.
Thousands of people from more than 80 nations, including Britain, other parts of Europe, China and the United States, have joined the ranks of Islamic State and other militant groups in Syria and Iraq over the past few months.
Islamic State seized large swathes of land in Iraq and Syria last June, including territory close to the Turkish border. A US-led coalition has launched air strikes to try and push the Sunni militant group back.