A Metro train departs the Gallery Place-Chinatown Metro Station on Jan. 11, 2018. (AP Photo/Alex Brandon)

Updated at 6:58 a.m.

Metro said a piece of track equipment, called a “stud bolt,” has been taken out because it was smoldering near the Gallery Place stop, according to a spokesman.

Metro briefly suspended its service on part of the Green and Yellow lines.

The transit agency said service was back on both lines, but riders should expect delays.

Updated at 6:34 a.m.

Metro trains are not running on the Green and Yellow lines between Archives and Mt. Vernon Square stops.

There is “fire department” activity at the Gallery Place station. Metro said it is requesting buses.

Original post at 5:45 a.m.

Riders on Metro’s Blue Line should expect delays Friday morning.

There is a problem with a switch at the Franconia-Springfield stop. It is not clear how long the delays will last.