WASHINGTON — It started with “have a nice day.” Now, it’s “enough is enough.” At least seven Metro bus drivers refused to drive their assigned routes on the X2 line Friday morning after saying their safety concerns are being ignored. “We’re not striking,” said Amalgamated Transit Union local 689 President Jackie Jeter. “What we’re saying is: Enough is enough, and we want you to keep us safe.” The union tweeted Friday morning that operators are not refusing to drive, but requesting a police escort to protect both drivers and passengers.

X2 operators are not refusing to drive. They are requesting police escort to protect them and riders #WMATA

— ATU Local 689 (@ATULocal689) September 1, 2017

Metro has a different take. In an email, the agency called the drivers’ actions “an unauthorized and potentially unlawful labor action that is significantly impacting riders on the X2 line.”

The action, and disagreement, stems from the Aug. 26 incident in which 38-year-old Opal L. Brown allegedly threw a cup of urine on a Metrobus driver. Brown told NBC Washington that she didn’t like the tone of the driver’s voice when the driver said “Have a nice day” to her. Metro and ATU Local 689 spent Friday trading accusations in dueling news conferences, emailed statements and tweets. “We have a great relationship with the union,” said Chief Ron Pavlik of the Metro Transit Police. “Ms. Jeter has a great relationship with us. She sends correspondence to our General Manager directly to me. They attend our local safety committee meetings.” Union spokesman David Stephen differed on Metro-Union safety communication. “Metro leadership is being completely dishonest,” he said in an email. “Put frankly, it is a bald-faced lie. Metro has not had a meeting with union leadership about safety in over a year, and the methods that Metro claims it is using to protect workers and riders are not working.” Less than an hour after the union sent that email, Metro sent out this tweet:

. Actually, most recent safety mtg was earlier *this week* w/GM, MTPD Chief & others. @ATULocal689‘s 1st VP & other reps were there. #WMATA

— Metro (@WMATA) September 1, 2017

Also, Metro and ATU 689 disagree on who is responsible for the X2 buses not showing up Friday morning. Metro’s statement blames “Metrobus Operators refusing to provide bus service in a disruptive and unlawful job action.” The union’s response: “The operators did not take X2 buses out of revenue service; that was a decision made by supervisors, and it was their decision that inconvenienced riders from getting to school and work.” So when will X2 buses roll again? Stephen told WTOP via email that “It is our hope and expectation that Metro leadership will address this issue [Friday].” Metro’s smartphone app said X2 buses resumed operating just before 11 a.m. but to expect “continued delays due to an unauthorized union labor action.” According to several tweets from the union, Brown is still free to ride Metrobuses, although she is banned from riding the X2 line. Multiple Metrobus operators have detailed various assaults by passengers, including being spat on and threatened.

We disagree with the order of the court to allow Opal Brown on Metro. Riders and workers are still in danger when she rides any bus or rail.

— ATU Local 689 (@ATULocal689) August 31, 2017

Metro said in a statement that a third of buses are equipped with protective shields and all new buses will have them installed. WTOP’s Reem Nadeem contributed to this report.