[This post will be updated]

10 a.m. Update: Metro says the Union Station stop is reopening.

Dan Stessel, Metro’s chief spokesman, said that delays on the Red Line will continue for at least an hour. Fourteen shuttle buses are taking passengers between Judiciary Sqaure, Union Station and New York Avenue stations.

Stessel said there are reports of “other power issues” in the area around Union Station.

“We are trying to connect the dots,” he said.

Original post: Trains are single tracking through Union Station due to an earlier track fire, Metro says. Trains are not stopping at the station and the Metropolitan Police department says Massachusetts Avenue NE at 1st and 2nd streets NE is closed due to a fire investigation.

Passengers are experiencing huge delays. Some travelers arriving from the eastern end of the Red Line are reporting trips of more than an hour and long waits in Metro tunnels.

Shuttle bus service has been established between New York Avenue, Union Station and Judiciary Square, according to Metro.

Another alternative for some riders is to travel on the Yellow and Green lines from Fort Totten to Gallery Place.

Dan Stessel, Metro’s chief spokesman, said the cause of the fire at Union Station was an “arcing stud,” equipment that is part of the third rail. The fire occurred on Track 1 — the Glenmont-bound side — within Union Station, he said.

Stessel said it “generated smoke within the station itself,” causing passengers to be evacuated. He said trains are currently running through the station without stopping.

Stessel recommended that riders “avoid [the Red Line] if you can.” There are no reports of injuries and he said it is unclear at this time what caused the fire. The fire department is on the scene and ventilating the smoke, using station fans that are built into tunnels.

“It is an active scene,” he said.

Check back for more details.