South Africa's President Cyril Ramaphosa has vowed to "expose" those undermining the unity of the governing African National Congress (ANC).

Mr Ramaphosa was speaking to trade unions outside the main city, Johannesburg, following newspaper reports of an alleged plot to unseat him.

Mr Ramaphosa used the language of war to describe the struggles still raging within the ANC.

"What kind of army are we," he asked, "when we take guns and start shooting each other?"

He didn't name names - but in recent days the ANC has been rattled by newspaper reports alleging that senior officials have been meeting in secret with the country's former President Jacob Zuma, looking for ways to weaken, or kick out, Mr Ramaphosa.

"Those dividing us must be exposed," Mr Ramphosa told delegates at a trade union congress.

The ANC's factional battles are becoming increasingly bitter and sometimes violent.

In theory they're about ideology. In practice, they're about power and the control of state budgets.

Mr Zuma was pushed out of office in February and now faces trial for alleged corruption. He denies the charges.

The ANC is looking to retain power in national elections next year.

But the infighting, and a shrinking economy, are testing Africa's oldest liberation party.