JOHANNESBURG -- Highly-skilled criminals are robbing vans transporting cash in South Africa at alarming rates. So far this year, there have been nearly 200 of these heists, oftentimes in broad daylight.

CBS News correspondent Debora Patta says the brazen attacks are carried out with "military precision" because gangs are recruiting people with specific skills.

"They will hire ex-police officers, they will hire ex-crime investigating officials. They have experts who are able to procure weapons, who are able to procure vehicles. The top getaway drivers," Patta said.

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Once the gangs arrive on the scene, they use heavy firepower including semi-automatic weapons and explosives. Meanwhile, the security guards assigned to the vans are outnumbered and lack both weapons and training.

There have been nearly 200 heists targeting vans in South Africa this year. CBS News

Patta spoke to author and analyst Anneliese Burgess, who says the criminals have come to expect a big payoff, with little chance of being arrested and prosecuted.

"The reason that this virus keeps mutating is because criminals see enormous value in ... these kinds of robberies," Burgess said. "One criminal said to me, 'I'll make more in one heist than you'll make in your whole life.'"

There's hope more will be done under South Africa's new President Cyril Ramaphosa. But Patta says many of the best investigators have left their positions after decades of corrupt rule under former president Jacob Zuma.

"You need evidence and so you need sophisticated detectives who can work with the prosecutors to bring these people to book and that is simply not happening in South Africa," Patta said.