Gauteng Transport MEC Ismail Vadi is being held hostage inside his department’s offices in downtown Johannesburg by about 20 metered taxi drivers.Police have now arrived on the scene while the angry group are gathered outside the building‚ stopping Vadi from leaving.Vadi was assaulted by some of the taxi drivers at the conclusion of a press briefing announcing that the department had started the process of issuing operating licensed to Uber driver partners where they can operate as metered taxis.A TMG Digital reporter said some of the metered taxi drivers had attended the briefing. A man had walked up to Vadi and shook his hand‚ before they started hitting him and shouting‚ asking him if he knew what he was doing.Vadi fled the room to escape the assault. A security guard who tried to step between the MEC and the protesters was thrown to one side as they tried to pursue the MEC...