WASHINGTON – Metro riders said a Yellow Line train’s doors opened before it arrived at a station Tuesday, and the transit agency says it is investigating.

Three riders reported doors opened on a Yellow line train before it entered the Reagan National Airport station Tuesday afternoon. The train was stopped at the time, but not yet in the station.

None of the riders posted pictures or videos of the incident.

Metro says they are aware of the reports on social media, but would not confirm whether or not it happened.

The train was taken out of service and all riders were put on the next train.