At approximately 17:45 on Sunday, an Israeli warplane fired a missile at a group of Palestinian civilians near al-Rahma Mosque in al-Nussairat refugee camp. As a result, 2 civilians were killed: Atiya Abdullah Mubarak, 56; and Hussam Hussein Abu Shawish, 37.
Hamas' Al Qassam website describes Atiya Mubarak as one of their mujahadeen, despite his age. He joined Hamas in 1998 and the Al Qassam Brigades in 2007. He participated in Cast Lead and worked on logistics behind sending terrorists to battle, "competing with the youth in jihad for the sake of Allah."
PCHR again:
At approximately 16:30, an Israeli drone fired a missile at a number of Palestinian civilians in al-Salatin Street in Beit Lahia, killing one of them, Fadi Mousa Sameer al-Qatanani, 29, and 6 others, including two children, were wounded.
The Al Qassam website says that "since Fadi was a child, he wished to carry a gun to fight the enemies of God, the Jews; constantly repeating slogans of jihad, his eyes yearning to jihad and martyrdom, and the castles of glory and honor and dignity."
He was a member of the Qassam Brigades for over ten years, working in smuggling tunnels as well as "repelling invasions" from Israel in northern Gaza.
Hamas says they are mujahadeen. PCHR says they are civilians.
Keep in mind that there are only several thousand Al Qassam Brigades members at the most, among a population of some 1.6 million in Gaza. If Israel was just randomly firing into "civilians" the odds of hitting a Qassam Brigades member is about one in 300.