Former Prime Minister Helen Clark says she's shocked by Israel bombing a densely populated refugee camp in north Gaza.

Israel has defended the strike, saying it successfully targeted a Hamas commander responsible for the October 7 attack on Israel.

Gaza's Health Ministry says the attack killed at least 50 Palestinians.

Clark is also a former head of the UN Development programme.

She says the past three weeks have been devastating.

"The main UN humanitarian agency in Gaza- 67 of their colleagues have been killed. They're among more than 8,500 dead."

LISTEN ABOVE

• Gaping holes left after Israeli airstrikes destroy apartments in Gaza
• United Nations call for ceasefire of 'no significance' to Israel
• Why New Zealand's response to the Israel-Hamas war has been 'minimal' so far
• 'Nothing is right': Gaza people 'robbed' of funeral rites amid devastation