WASHINGTON — Metro service on the green and yellow lines is suspended on what is already a busy traffic day due to the arrival of Pope Francis.

Green line service is suspended between U Street and Fort Totten and all yellow line service begins and ends at Mt. Vernon Square. Metro says shuttles are in service.

Commuters leaving Nationals Park are advised to ride the green line and switch to the red line at Gallery Place if they need to get beyond U Street.

Metro says the issue is due to a third rail power outage and power crews are trying to troubleshoot the issue.

According to audio from a Metro train conductor, the outage occurred between the Columbia Heights and the Georgia Avenue stations.

D.C. firefighters evacuated the affected train, which stopped 100 feet away from the Georgia Avenue station, according to Metro Transit Police.

Metro officials say it will take some time to find the source of the outage and restore power.

Metro is advising riders to avoid delay by taking the red line between Gallery Place and Fort Totten.