The Australian Greens say an attack on a UN school, designated as a shelter, makes it clear nowhere in Gaza is safe as long as the fighting continues.

"It is devastating to hear of more deaths and injuries, in what was meant to be a safe place for civilians in Gaza," said Greens Leader Christine Milne.

"This attack must be strongly condemned and I echo the UN's calls for the immunity of UN premises in Gaza, and humanitarian law, to be respected.

Greens Leader Christine Milne has expressed disappointment at a likely split within the Labor party, on the use of the UN accepted term ‘Occupied Palestinian Territories' for the illegal settlements built after 1967, which contravene the Fourth Geneva Convention.

The Labor party blocked a Greens-Xenophon motion calling on the Foreign Affairs Minister to publically acknowledge these facts.

The Australian Greens say it was not a "bold move" to withhold support from a UN war crimes investigation, but rather a shameful demonstration that Australia is appeasing the government in Sri Lanka to further Tony Abbott's domestic policies on asylum seekers.

"The Rajapaksa government is, in my view, an elected dictatorship. It only came to power because the Tamils boycotted the election," said Greens Leader Christine Milne.