South Africa unrest over ANC's Tshwane candidate

Burning vehicles have been blocking several of the roads around Pretoria

Police are battling to quell violence that has broken out in the area around South Africa's capital, Pretoria.

A government statement calling for calm said police officers "came under fire as protesters allegedly attacked their car with stones". Trouble broke out in the Tshwane area reportedly over the mayoral candidate chosen by the governing ANC for August's elections.

The tension relates to factionalism within the party, analysts say. Local media are showing pictures of burning barricades blocking main roads. South Africa's government has called for dialogue to sort out the problem.

Some ANC members in the city are said to be angry that current mayor Kgosientsho Ramokgopa was pushed aside in the nomination process. But Mr Ramokgopa has said he is happy with the selection of Thoko Didiza, reports South African news channel EWN.

"I really want to call for calm [and] call for people not to disrupt other people's lives. Let's allow this election to unfold in a free and fair manner," he is quoted as saying.