Commuter service Gautrain resumed full services on Friday after hundreds of passengers were earlier left stranded when a power outage forced trains to stop running halfway between Johannesburg and Pretoria and on the route between the Sandton district and OR Tambo International Airport.
"We are pleased to advise that power has been restored and the train service is now fully operational. We apologise for the inconvenience caused by the service disruption this morning," Gautrain said in mobile text message to customers.
In an earlier message, it said the electricity disruption had forced it to halt the train service between its Midrand and Park stations and between Sandton and the country's biggest airport, calling on passengers to make alternate transport arrangements.
The opposition Democratic Alliance slammed the company for failing to communicate the problems timeously to commuters.
"It is unacceptable that commuters using the Gautrain were only informed 20 minutes after the power failure that there would be a limited Gautrain service," DA spokesperson for roads and transport in Gauteng province Janho Engelbrecht said.
He said he would table questions in the provincial legislature for Gauteng member of the executive council for roads and transport Jacob Mamabolo to ascertain the reason for Friday's power outage and why Gautrain did not have a backup power supply.
Scores of frustrated commuters took to social media, blaming both Gautrain and state electricity utility Eskom for their failure to get to work and school on time, while others said they had missed their flights.
Eskom said on Thursday night it would implement what it calls stage 2 load-shedding from 10 pm until Friday morning, involving the suppression of 2,000 MW of demand through rotational powercuts to avoid tripping the national grid.
It said it had lost three generations units earlier in the day and had to use emergency reserves throughout.
"As a result our emergency reserves are now at critically low levels and need to be replenished overnight in order to meet tomorrow’s (Friday's) forecasted demand in electricity," the company said.
Eskom, whose infrastructure is in a fragile state due to years of poor maintenance, was forced to implement loadshedding earlier in the year and for a week last month as some of its generating units failed.
The company is also in financial dire straits partly due to mismanagement by former executives who were implicated in corruption, while several municipalities and state-owned power utilities from neighbouring southern African countries owe it millions of rand in unpaid bills.