Hamas, the Iran backed Islamic terror group in Gaza, has cracked down on competing Islamic terror groups. Partly, this is to eliminate any potential threats to their control of Gaza, and partly to try and force some of these other terrorists to halt rocket and mortar attacks on southern Israel. Not only are these attacks generally harmless, but they delay a ceasefire deal with Israel. Hamas wants this so it can build up a large enough supply of rockets, guided missiles and other weapons so that, in their next major battle with Israel, they will have some success.
But in the meantime, the smaller Islamic terror groups are not standing idly by. One of these groups, the Al Aqsa Martyrs' Brigades, reported on their website that, after Hamas seized the weapons of Brigade members, these men took all the money they had (including that required, as the website reported, to buy food for their children), and sold their wives jewelry (normally an emergency reserve, to be sold only for the most dire of family emergencies) to buy replacement weapons. As hard as Hamas tries to gain complete control over Gaza, there is still a black market in weapons.
Al Aqsa Martyrs' Brigades is part of the Fatah organization, which is the principal rival to Hamas in the Palestinian community. Fatah controls the West Bank, which in effect splits control of the Palestinian community between Fatah and Hamas. Both groups support terrorism against Israel. The main difference is that Hamas is more radical, and is backed by Iran. Fatah is backed by the UN, many Western countries, and, at times, Israel.