South African President Jacob Zuma, facing a firestorm over the deaths of 13 soldiers in a coup in the Central African Republic, said Thursday he was withdrawing troops from the restive nation.

Zuma is facing thorny questions over why South Africa had troops in the country in the first place, amid accusations of dodgy deals with ousted president Francois Bozize.

"We have taken a decision to withdraw our soldiers," Zuma said as pressure rose over South Africa's biggest military loss since the end of apartheid.

Thirteen troops died and 27 were wounded on March 23 when they came under fire from around 3,000 Seleka rebel fighters near the capital Bangui.

Zuma said the decision to pull out remaining troops was made because the overthrow of Francois Bozize's government effectively ended a bilateral military deal.

"Our mission was to help train the soldiers, since the coup and the self-appointment of rebels, it was clear that the government is no longer there," Zuma said, according to state broadcaster SABC.

As the situation in Central Africa deteriorated last year, South Africa had 26 soldiers on the ground to help with military training in the troubled nation, which has suffered repeated coups since independence in 1960.

In December a decision was taken to send around 200 more South African troops to protect the trainers and military equipment.

It emerged that there was a mandate to protect Bozize, who himself seized power in a coup in 2003, and later won a flawed presidential election.

With the South African government offering few details about the mission, accusations have swirled that it had morphed to match business interests of the ruling ANC.

Allegations also surfaced in Bangui that Zuma and Bozize had signed accords giving South African businesses access to oil, diamond and gold riches in exchange for protection.

Pretoria has fiercely denied this.

"Do you think we would take the South African National Defence Force, send them out to go and defend or protect what belongs to individuals? It's so incorrect," defence minister Nosiviwe Mapisa-Nqakula told lawmakers in Cape Town.

South Africa's security minister Siyabonga Cwele visited Bangui to meet the rebel leadership on Thursday. He also denied Pretoria had sent troops for mining deals.

"The government of South Africa doesn't have any mining contracts," he said, adding that individuals might.

"We were there for the peace and stability of Africa," he said.

At the meeting new Central African strongman Michel Djotodia expressed his condolences for the deaths of the soldiers.

Meanwhile defence minister Mapisa-Nqakula did acknowledge that intelligence failed to predict the attack, but insisted the South African base had only come under fire because it was on the rebels' route to Bozize's palace in Bangui.

"They had gone to Central African Republic to assist with the post-conflict recovery of that country. We never anticipated that we would be attacked," she said.

Worrying reports had emerged that some of the rebels killed in the fight with South African troops were child soldiers.

Mapisa-Nqakula said recruiters of children for armies should be indicted but that her soldiers were right to defend themselves.

"If a child is a rebel soldier and is carrying an AK-47 and shoots at you are you going to wave your hand and say take a sweet and blow kisses? You will not do that," she said.

If fired at in battle "you fire back, you hit back and you make sure you hit hard. If it is a child, that's unfortunate," she added.

She also said the protection of Bozize, which grew out of a 2007 pact, ended in 2008. South Africa did not help him flee Bangui, she added.

Lieutenant General Derrick Mgwebi said the attacking forces were carrying heavy weaponry and included fighters who were "not coming from Central African Republic."

Some were wearing Arabic-style dress, he told AFP.

Bozize has accused neighbouring Chad, a former ally, of helping the rebels oust him.

Opposition parties have welcomed the withdrawal but called for an independent commission of inquiry and full explanation of why troops were deployed.

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