Police in South Africa have opened fire during clashes with striking workers at the Marikana platinum mine, leaving seven people dead.

Police opened fire after miners carrying machetes defied an ultimatum to disarm, reports from the scene say.

The mine, owned by Lonmin, has been at the centre of a violent industrial dispute exacerbated by inter-union tensions.

Earlier this week nine people died in clashes there.

During the clashes, missiles - thought to be either petrol bombs or grenades - were thrown at police, who responded by opening fire, eyewitnesses said.

"There are bodies on the ground, I saw one with a bullet wound on the forehead," one eyewitness told the BBC.

The recent violence has been triggered by a turf war between the long-established National Union of Mineworkers (NUM) and the newly-formed Association of Mineworkers and Construction Union (AMCU), which is more militant, analysts say.

BBC