ANC secretary general Gwede Mantashe on Friday warned of anarchy if incitement to violence was tolerated.

"We cannot allow lawlessness to roll over the country and think it should be rewarded and therefore begin a norm in society," he told reporters in Pretoria.

"Our appeal we are making to the state -- people must exercise their rights but violence should not be an option when exercising those rights."

Mantashe was briefing reporters at the St George's hotel, in Pretoria, before the start of the African National Congress' national executive committee meeting.

Mantashe said the NEC would focus on a number of issues including the situation at platinum mines.

"We are paying attention to the Marikana situation and its ramifications," he said.

"We are not trying to cover what would be covered by the Commission of Inquiry. We are looking into the political economy of the development and the long-term impacts on society in general."

Mantashe added that it was not the business of the NEC to deal with incitement but that of the state.

Incitement is a criminal offence and it is written as such in the Constitution, he added.

"Tolerance to incitement and agitation is something that can lead to anarchy," he said.

"Once anarchy rules society, that society degenerates, and that society collapses in the long run."

Mantashe said the NEC would also discuss issues around the centenary celebrations of the ANC.

He said the meeting would discuss whether the celebrations helped society understand the history of the ANC, and the party itself.

"We are looking into the preparations for the national conference in December," he added.

Mantashe said there would be at least two special NEC meetings in the run-up to the Mangaung elective conference, to ensure a "smooth national conference".

President Jacob Zuma, National Assembly Speaker Max Sisulu, ministers Trevor Manuel, Lindiwe Sisulu, Fikile Mbalula, Susan Shabango, Jeff Radebe, Nathi Mthethwa and Naledi Pandor were among those seen entering St George's hotel.

At the head of the table were Zuma, Mantashe, deputy president Kgalema Motlanthe, ANC treasurer general Mathews Phosa and deputy secretary general Thandi Modise.

Before the session started, Zuma was seen walking through stalls selling ANC merchandise set up at the hotel.

Talking on his cellphone, the president kept looking at a black ANC shirt, while security stood nearby.

ANC Youth League deputy president Ronald Lamola was seen arriving alone.

The NEC meeting is expected to run until September 16.