All of San Francisco's famed cable cars are running again after mechanical problems that began Friday night and continued into Saturday forced the closure of some lines.

San Francisco Municipal Transportation Agency spokesman Paul Rose says cars on the Powell-Mason and Powell-Hyde cable line started rolling again around 1 p.m. Saturday.

All cable car service was stopped Friday night because of mechanical problems.  Service resumed early Saturday, then service on the Powell-Mason and Powell-Hyde cable line was stopped again because of what was described as an equipment problem.

Rose says service resumed again when crews were able to repair a strand in a cable.

The historic cable cars are an especially popular attraction for tourists.  The cars do not operate on their own power, but are moved by a mechanism that grips cables that run beneath San Francisco's streets.