It's not a surprise that ISIS could easily enter the Philippines. Why? Government supports them just to lead a rebellion against the current administration. At first, Maute, Abu Sayaff and NPA are the one terrorizing the south part of the Philippines especially in mindanao. This group cannot operate without sponsors. Philippines is already under Siege way back Marcos terms. It just so happen that this ISIS can caused a lot of damage to a small country like Philippines.
Government do not help these guys, and if they are, do you have a proof? This is not a movie where the enemies is just standing right behind your ears, this is the real world. If you will be blaming these siege at our government, then you can, but we can't do anything about it but to pray and hope that the civilians there are safe and that these skirmish will end fast.