"Israeli forces have operated with near complete impunity for so long that unlawful killings and other flagrant violations of worldwide law have become the norm", Ayed Abu Eqtaish, Accountability Program director at DCIP said in the report.
The deaths of two of its fighters could trigger an escalation between Hamas and Israel. The shelling killed two Palestinians.
The Palestinian news agency Wafa reported that the incident was "expected to destroy Egypt and the UN's efforts to achieve a long-term ceasefire" between Israel and Hamas.
Israel has fought three wars with Palestinian militants in Gaza since 2008 and says the blockade is necessary to keep them from obtaining weapons or materials that could be used for military purposes. The video then cuts to separate footage of a shell hitting the post and an explosion.
Sources confirmed that Murjan and al-Silawi were members of the Izz al-Din al-Qassam Brigades, the armed wing of the Hamas movement.
The cross-border incident came after a delegation of senior Hamas officials visited Gaza to discuss a ceasefire agreement with Israel proposed by the United Nations and Egypt.
Smoke rises following an Israeli attack on the Gaza Strip as it seen from the Israeli side of the border, May 29, 2018. By the end of July, over 155 Palestinians had died by Israeli fire and thousands were injured, according to the Palestinian health ministry in Gaza.