A report of a possible bomb Wednesday at a South Loop CTA station temporarily shut down L service for almost an hour during the evening rush.

A woman at the Roosevelt Red Line station told a CTA employee that she overheard a man say he had a bomb, according to Chicago police. The CTA employee alerted a superior, who then contacted police.

A police K-9 unit was called at 6:09 p.m. to the station in the 1100 block of South State Street, police said. The unit swept a train, but did not find a bomb.

The woman who notified authorities had already left the station, police said. No arrests have been reported.

Orange, Green and Red Line trains were halted about 6 p.m. at Roosevelt due to police activity, according to the CTA. The agency announced at 6:45 p.m. that trains were running with major delays.