Smoke at the L’Enfant Plaza Metro station has forced an evacuation and led Metro to shut down the Green and Yellow lines through downtown.

There are no reports of injuries at the moment, according to D.C. Fire and Emergency Medical Services Timothy Wilson. “We are trying to remove passengers from a disabled train,” he says. “We’re trying to get to the incident scene itself.”

It was not immediately clear what caused the incident, or its severity. Local 36 of the D.C. Fire Fighters Association tweeted that a “mass casualty incident” has been declared at L’Enfant Plaza, although Wilson was not able to confirm that. A mass casualty incident simply means that multiple people may need to be treated, says Wilson.

Mass Casualty incident declared at L'Enfant Metro Station.

— DC Fire Fighters L36 (@IAFF36) January 12, 2015

Metro has evacuated the station and shut down portions of the Green and Yellow lines. Green Line service is suspended between Navy Yard and Mt. Vernon Square; Yellow Line service is suspended between Pentagon City and Mt. Vernon Square. Blue, Orange, and Silver Line trains are bypassing L’Enfant Plaza.

Evacuated from lefant station #unsuckmetro #wmata pic.twitter.com/NfFDWcn8jT

— Del. Lesley Lopez (@LesleyJLopez) January 12, 2015

That was easily the worst metro ride of my life pic.twitter.com/a5EnGeRzMQ

— Jonathan M. Rogers (@JRogers202) January 12, 2015

Update 5:50 p.m.: Green and Yellow Line service has been restored at Gallery Place-Chinatown to and from Greenbelt. Service remains suspended between Gallery Place and Navy Yard on the Green Line, and between Gallery Place and Pentagon City on the Yellow Line.

Photo by Darrow Montgomery

DC Fire Fighters Association, Local 36