Just days after the SFMTA passed some new regulations overseeing the city's emerging jitney scene, the one remaining private shuttle bus company has abruptly shut down operations.

Ford-owned commuter shuttle Chariot announced the temporary closure of their service in an e-mail sent to customers Thursday. According to the Chronicle, it reads, in part: "We sincerely apologize for the inconvenience and will alert you immediately once we reopen service, as we expect to resolve this disruption quickly."

The full e-mail, which Chariot posted to Twitter, goes on to say that "even though Chariot is in full compliance with all regulations," they've shut down for now because they "received an order from a regulator to temporarily suspend service." The SF Business Times explains that the shutdown comes after Chariot failed three California Highway Patrol safety inspections.

The future of the service was already in question, as the SFMTA was considering banning it and other private commuter shuttle operations from running along already-established public transit lines. Their main concern centered on how Chariot could potentially be siphoning off funds that would normally be going to public transit. According to the Examiner, a draft version under consideration by the SFMTA said that any routes matching a current Muni route by 75 percent or more would be outlawed — with the exception of Chariot's current lines which, surprisingly enough, could potentially be grandfathered in.

This latest batch of regulations from the SFMTA happened as a result of a slew of complaints about how the now-ubiquitous shuttles were double parking and blocking Muni stops and driveways. According to the Business Times, as part of the new regulations passed on Tuesday, Chariot has to now submit operating data to the SFMTA and begin offering wheelchair-accessible shuttles. Moreover, they say that they had nothing to do with the service's ordered shutdown yesterday.

Related: Chariot To Add New Routes And 50 Additional Vans Following Acquisition By Ford