At least one Hamas terrorist was killed and several more injured this morning in a large explosion. According to Ma'an English, it was in a Khan Younis "military post."
Wafa (Arabic) adds that it was in a Hamas "training camp" in the former settlement of Netzar Hazani, and the early reports make it sound like the number of casualties may increase.
This brings the number of PalArabs violently killed by each other in 2007 so far, by my count, up to 157.
UPDATE: Ynet reports one dead, seven injured, some critically. Ma'an now reports eight injured, including a child.
UPDATE 2: A Salafi sheikh was murdered in Gaza City by four gunmen, a relative was injured and an Internet cafe was blown up. 158.