Cape Town – A 15-year-old Cape Town girl, believed to be travelling to join Islamic State (ISIS), had become increasingly political over the last month, even confiding in her friends that she would be joining the militant group.

According to media reports the girl had confided to friends that she planned to join ISIS and relatives had noticed she had become increasingly politicised in the last month.

A spokesperson for her family declined to comment.

The teen, believed to be travelling to join ISIS, was stopped from taking a flight in Cape Town, the state security ministry said on Monday. It was SA’s first known detention linked to the militant group.

The ministry said in a statement it was investigating whether ISIS, which has overrun large areas of Syria and Iraq, had a recruitment network in South Africa.

"The family of the young girl has been spoken to and after being debriefed by officials the young girl has been released back into the care of her family," it said.

The teenager had tried to take a domestic flight on Sunday to Johannesburg.

The ministry did not give her name or say where she was heading after that, but the Star newspaper reported she had been planning to fly to Turkey before travelling by road to join ISIS in Syria.

Thousands of people from more than 80 nations, including Britain, other parts of Europe, China and the United States, have joined the ranks of ISIS and other militant groups in Syria and Iraq, many travelling through Turkey.

Young women have joined the group to marry its fighters

The teenager had been stopped at Cape Town International Airport after evidence was found in her bedroom indicating she had been in contact with ISIS recruiters, the ministry said.

It did not give any information on how the girl may have been recruited but said it was concerned about the use of cyber technology by terrorist groups.

‘An exception’

The Cape Town-based Muslim Judicial Council (MJC) believes that the recent incident of a teenager travelling to join the Islamic State (ISIS) is “an exception”.

Nabeweya Malick, MJC spokesperson, said: “We are all shocked but believe this case is an exception.

She said: "With the influence of technology and the cyber world our children are constantly connected to, we are very concerned that young people, unfortunately, see ISIS members as some sort of heroes."

The government has long been concerned about the radicalisation of South Africa's largely conservative Muslim community and of the country being used as a launching pad for Islamist attacks.

The statement said State Security Minister David Mahlobo "wishes to reassure South Africans that the country will not allow itself to be used as a recruitment platform".

In the mid-1990s, a group of mostly Muslim men set up a vigilante anti-crime group called The People Against Gangsterism and Drugs (Pagad), which carried out a series of attacks at synagogues, gay nightclubs and tourist attractions.

Some security experts said the group had ties with Middle Eastern Islamist groups. A police operation in 1998 largely ended Pagad's attacks.

Briton Samantha Lewthwaite, whose husband Germaine Lindsay was one of the suicide bombers in the 2007 attacks on London's transport system, spent long periods in South Africa from 2008, according to government officials and local media reports.

Lewthwaite, dubbed the “White Widow”, had travelled on a fraudulently acquired South African passport. She is wanted by Kenyan police on terrorism related charges.