Facebook is suing BlackBerry for patent infringement related to a voice-messaging technology, in the latest round of the legal battle between the two companies.

In a complaint filed filed Tuesday in San Francisco federal court, Facebook accused BlackBerry of stealing its voice messaging technology, among other patented processes. Facebook is seeking unspecified damages for infringement of six patents.

BlackBerry didn't comment on the suit yet.

In addition to the voice-messaging patent, Facebook cites infringement of patented technology that improves how a mobile device delivers graphics, video and audio and another that centralizes tracking and analysis of GPS data.

In March, BlackBerry sued Facebook in federal court in Los Angeles, accusing the social media giant of infringing on its mobile messaging patents.

BlackBerry claimed Facebook made unauthorized use of its technology in its own instant messenger service, Facebook Messenger, and in WhatsApp Messenger and Instagram.