Copper thieves should be charged with economic sabotage rather than common theft, Transport Minister Fikile Mbalula suggested in Parliament on Tuesday.

Mbalula told the portfolio committee on transport that stolen copper rail cables were exported to India through Mozambique by syndicates, and simply charging suspects with theft failed to properly address a crime crippling commuter rail services.

"This sort of crime must see you sent to jail. It is economic sabotage," he said.

Mbalula said if cable thieves were arrested, they were soon released on bail and likely to return to stealing cables "that afternoon" because it was so lucrative.

He said it was clear that employees of the embattled Passenger Rail Agency of South Africa (Prasa) were colluding with the thieves and syndicates.

The South African Chamber of Commerce and Industry estimates that cable theft cost the economy somewhere between R5-billion and R7-billion a year.

Mbalula also called for proper intelligence to be done to determine who the masterminds behind the burning of train carriages were. He said it beggars belief that the teenage suspects caught for torching 18 carriages at Cape Town central station in November last year, told police they were "playing". 

"It is 3am and they tell you they were playing. At 3am!"

The arson attack caused damage of more than R60-million rand. 

At the time, provincial safety member of the executive council (MEC) Albert Fritz said in future those involved in attacks on the railway system could be prosecuted under the recently adopted Critical Infrastructure Protection Act, which provides for prison sentences of up to 20 years.