Palestine Press quotes Gaza Salafi officials saying that Hamas staged a series of raids against prominent Salafist sites in Gaza this morning, arresting a number of leaders.
Hamas has a history of animosity and attacks towards these groups, the only terror groups remaining in Gaza that do not cooperate with Hamas.
One of the Salafi groups, the Masada al Mujahideen organization, has blamed Hamas for the Israeli attacks against their leaders on Friday night, implying that Hamas tipped the IDF off. Israel's Terror Watch website makes the same claim that Hamas acted as an informer to Israel to rid themselves of their rivals. This seems unlikely, although it is possible that Hamas is "turnng" the "collaborators" that they have already caught to feed the IDF intelligence for those they want to eliminate.
(h/t Yoel, Challah Hu Akbar)