OAKLAND -- BART has resumed regular service after major delays between West Oakland and the Embarcadero station in both directions, an agency spokeswoman said Monday night.

There was a report of haze in the TransBay Tube, but BART crews who investigated found nothing and the system was deemed safe, said BART spokeswoman Alicia Trost.

Delays began about 7:35 p.m. and trains resumed normal service about 8:10 p.m., Trost said.

For about 40 minutes, trains were single tracking, which means they had to wait for a train to come through the tube before another one could go back on the same tracks.

No one was injured.

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