A growing problem in Gaza, for the Palestinians there (especially Hamas, the radical group that runs the place) and neighboring nations, is the growing number of Islamic terrorists moving in. Hamas has made Gaza a sanctuary for Islamic radicals. So has Somalia and the tribal territories of Pakistan. But Somalia is in chaos, and Pakistan's tribal territories are under heavy attack. Thus while Gaza is small, and under constant threat of Israeli attack, it is relatively safe. And the tunnels into Egypt give these terrorists access to the rest of the world, via an underground network of criminals and Egyptian Islamic radicals who will, for a price, help you get out of the country, or get weapons, equipment and false ID.
The Egyptians are not cooperating with this arrangement, as many of the Islamic radicals in Gaza consider the Egyptian government an implacable enemy. That's certainly true, as Egypt destroyed the radical wing of the Moslem Brotherhood in the 1990s (some of the survivors joined al Qaeda in Afghanistan). Four months ago, the government uncovered a network of 49 Hezbollah terrorists planning attacks inside Egypt. About half the suspects got away, some into Gaza.
Hamas does not want to run a sanctuary for terrorists, but as an Islamic radical organization, it does not want to get into wars with other Islamic terror groups. This is all too easy a trap to fall into. In most areas where Islamic terrorists are active, factions among the terrorists are fighting each other. This does not get a lot of media play, but it gets a lot of Islamic terrorists killed. Think of it as a dirty little secret in the terrorist world. Hamas would rather not join this club, at least not in a big way.
Hamas has not been able to avoid terrorist-on-terrorist bloodshed. The most recent incident had Hamas gunmen fighting with members of Jund Ansar Allah, a group that accuses Hamas of not being radical enough. That's partly because Hamas has decided to obtain a ceasefire with Israel, so that the Hamas arsenal can be built up (especially with long range Iranian rockets), along with defenses in Gaza. Hamas has a vague plan to make a large scale attack on Israel, and feels its chances would be much enhanced if they could only stockpile enough weapons. Thus Hamas feels compelled to pressure, even kill, other terrorists who will not cease attacking, or trying to attack, Israel. So far, Hamas has been able to avoid large scale bloodshed with fellow terrorists. But this is not expected to last. The battle with Jund Ansar Allah left 21 dead (including six Hamas police) and 40 Jund Ansar Allah members arrested. Hamas blamed its rival Fatah for arming and encouraging Jund Ansar Allah. But groups like that have no problems finding arms, or encouragement to fight. Hamas will have a hard time clearing the Islamic radical competition out of Gaza, and many Hamas members do not like fighting other radicals.