Breaking news out of Twitter this afternoon, four key product managers have just been let go, we’ve learned. The move was led by Jack Dorsey and will see key product guys Kevin Cheng, Josh Elman, and two others we’ve yet to confirm, leave the company.

Twitter refuses to comment on any specific names and would only say that “some people have left the company and we appreciate their contributions”. But we’ve independently confirmed that both Cheng and Elman are two of those no longer with the company. Both of these guys have been vital to the Twitter product over the past couple of years. Cheng, for example, was key on the “New Twitter” project. Elman was previously with Facebook.

This move is said to be led by Dorsey as a final measure to remove those still closely affiliated with the old Evan Williams, Biz Stone, and Jason Goldman regime. Those three, of course, all left Twitter in recent months and just re-launched the Obvious startup incubator where Twitter was originally born.

Reached, Cheng and Elman both declined to comment.

Update: We’ve now confirmed that Anamitra Banerji (@anamitra), who started Twitter’s ad platform, and Jean-Paul Cozzatti (@jeanpaul) will round out the foursome of PMs who are leaving.