Lyft is pulling its pink electric bicycles from the streets of San Francisco, just two months after deploying them, because some of these bikes caught fire while in use.

The bikes, officially labeled Lyft bikes and accessible under the newly rebranded Bay Wheels platform (formerly Ford GoBike), are one of the ride-hailing company’s new dockless mobility options, all operated by the Lyft-owned bikeshare company Motivate. Lyft previously pulled its electric bikes off city streets nationwide back in April after a braking malfunction proved extremely dangerous to riders.

Lyft has spent months working on redeploying the fleet so that it could support both docked, non-electric bikes and dockless electric ones. (The electric ones are similar in style and operation to Uber’s Jump bikes, and have pedal-assist motors powered by built-in batteries.) The electric bikes are locked to public bike racks within a reasonably large permitted zone in San Francisco and can be picked up off the street. The new bikes have been operating in San Jose since June and in Oakland since July 12th, shortly before the San Francisco debut.

But on July 27th, a rider named Zach Rutta posted a photo to Twitter of a charred Lyft bike. It’s unclear how many other reports of battery malfunctions or literal bike fires occurred, but the San Francisco Examiner reports that a second case occurred today. That second case may have prompted Lyft’s immediate action.

The company is pulling the bikes to investigate the issue, though Lyft says there have been no reported injuries due to the e-bikes. Lyft won’t rule out possible vandalism, either. “Out of an abundance of caution, we are temporarily making the e-bike fleet unavailable to riders while we investigate and update our battery technology,” a spokesperson tells The Verge. “Thanks to our riders for their patience and we look forward to making e-bikes available again soon.” The bikes will also be pulled from San Jose and Oakland.

Lyft is trying to maintain exclusivity over dockless e-bikes in San Francisco

Right now, Lyft is trying to argue it has the exclusive right to deploy dockless electric bikes on the streets of San Francisco, potentially pushing out competitors like Uber’s dockless Jump e-bikes. The company sued the city in June to prevent San Francisco from seeking other third-party contracts; Lyft claims it has a 10-year contract that gives it sole control of the dockless bikeshare market.

The city has countered by saying Lyft misunderstood the terms of its contract with the Bay Area Metropolitan Transportation Commission (a contract initially secured by Motivate, which Lyft acquired last year). The city maintains Lyft’s exclusivity concerns only docked bikes, like its existing Bay Wheels (formerly Ford GoBike) stations where you physically have to pull a bike out of one rack and put it into another at the end of your ride.

Lyft was set to redeploy its e-bike fleet in July. After a legal tussle that resulted in a preliminary injunction against the city, barring it from seeking outside contracts, Lyft was granted an interim permit to put its e-bikes on San Francisco streets. But the burning bikes could jeopardize Lyft’s ability to potentially have exclusivity over bikeshare options in San Francisco.