Hamas denies it up and down. Nonetheless, there are growing signs that the Islamist movement, which is based in the Gaza Strip, is continuing to cooperate with other jihadi terror groups that are affiliated with Islamic State (ISIS), especially those that have been operating in the Egyptian peninsula of Sinai in recent years.
This cooperation, according to Palestinian Authority security sources, is the main reason behind the ongoing tensions between the Egyptian authorities and Hamas. These tensions have prompted the Egyptians to keep the Rafah border crossing mostly closed since 2013, trapping tens of thousands of Palestinians inside the Gaza Strip.
In 2015, the Egyptians opened the Rafah terminal for a total of twenty-one days to allow humanitarian cases and those holding foreign nationalities to leave or enter the Gaza Strip.