(Katherine Frey --The Washington Post) (Katherine Frey/The Washington Post)

Metro General Manager Richard Sarles said employees who are found to jam intercoms on rail cars could face discipline.

After last week’s Metro board meeting, Sarles said that “if in the future, employees are found” to be jamming the intercoms on rail cars they “will face disciplinary action.”

The move comes after the transit agency received tips that employees were sticking things into intercoms that allow passengers onboard a train to communicate with the train operator in an emergency, causing the devices not to work.

Operators had jammed intercoms on some of the 2000, 3000 and 5000 rail car series after they received new digital radios that created interference that affected the intercom. Operators found the noise “a nuisance,” according to Metro spokesman Dan Stessel.

Metro admitted earlier this month that it had known since at least 2009 of some problems with the intercom system but hadn’t addressed the issue. The issue came to light in June when riders were unable to reach the train operator over the intercom after a fight broke out on a Red Line train.