(Linda Davidson – The Washington Post)

Metro officials said human error at its rail operations control center is the cause of two trains going down the wrong tracks.

The two separate incidents happened in the last week.

Around 3:30 p.m. Tuesday, a train that was marked as an Orange Line train went down the Blue Line tracks. Blue and Orange line trains share a track for portions of the system but they split apart at Rosslyn. The Blue Line heads south to Franconia-Springfield, while the Orange Line heads west to Vienna.

The train stopped at Arlington Cemetery, and passengers were off-loaded and rerouted on another train, according to Metro spokesman Caroline Lukas.

“It was an inconvenience,” she said. “They were off-loaded, and they had to double back.”

“Instead of it acting like an Orange Line train, it acted like a Blue,” she said. The incident happened because of a “signal issue,” she said. Lukas said she did not have more details about what caused the problem and said she “would assume” the incident is being investigated.

People on social media outlets raised concerns Tuesday about safety after the incident, but Lukas responded, “I know some folks on Twitter are trying to make this a safety issue but this was never a safety issue.”

On July 3, there was a similar incident.

An Orange Line train was “taken out of service at Arlington Cemetery after it was inadvertently routed to the Blue Line,” according to a statement Metro spokesman Dan Stessel gave to WJLA which first reported on the incident.

Stessel said the July 3 incident “did not delay other trains, and passengers aboard the affected train experienced a 12-minute delay in their trip. At no time was this a safety issue.”

On Tuesday afternoon, when asked if the two incidents were similar, Stessel wrote in an e-mail that it was “not known yet.”

He said they were “similar in effect, but there are different scenarios that can cause.” He said Metro “won’t know until playback is completed” more details of what happened.

On Thursday, Metro’s top officials briefed the board of director’s safety and security committee on the recent incidents. After the meeting, Metro gave more details on what occurred and assured riders that there was not a safety risk of trains running into each other because of computerized systems that track trains’ whereabouts.

In the July 3 incident, Metro spokesman Dan Stessel said a train had wrongly been identified in the operations control center as going down the Blue Line but it was destined for the Orange Line.

The control center “misidentified the train as a Blue instead of an Orange so it was sent down the Blue Line,” Sarles said of the July 3 incident.

In the other incident, Stessel said, a Blue Line train had mechanical problems and a technician couldn’t fix it. The train was reversed on the tracks and sent to the New Carrollton rail yard on the Orange Line. But after the train was moved, personnel in the operations control center did not reset the computerized signals that identifies Orange and Blue line trains. The next train that approached the area was an Orange Line train but the signals were still marked for a Blue Line train.

Sarles said, “we don’t want to inconvenience customers by taking them to the wrong stations.” He said his staff is reviewing the incidents to see if there should be disciplinary action taken.

The incidents come as Metro has recently reported to its board that it has seen an uptick of train operators running red signals.

This post has been updated.