Gaza conflict: Who is a civilian?

The bloodied children are clearly civilians; men killed as they launch rockets are undisputedly not. But what about the 40 or so young Hamas police recruits on parade who died in the first wave of Israel's bombing campaign in Gaza?
And weapons caches are clearly military sites – but what about the interior ministry, hit in a strike that killed two medical workers; or the money changer's office, destroyed last week injuring a boy living on the floor above?
As the death toll mounts in Gaza, the thorny question is arising of who and what can be considered a legitimate military target in a territory effectively governed by a group that many in the international community consider a terrorist organisation.
This is also the group that won the Palestinian legislative elections in January 2006 and a year later consolidated its control by force.
So while it was behind a campaign of suicide attacks in Israel and fires rockets indiscriminately over the border, it is also in charge of schools, hospitals, sewage works and power plants in Gaza.
International law
Israel says it is operating totally within humanitarian law, but human rights groups fear it is stretching the boundaries.
And as ground forces clash in the heavily-populated Gaza Strip, the questions will become more pressing.
International law’s rules on keeping civilian casualties to a minimum are based on the distinction between "combatants" and "non-combatants".