The United Nations has decried strikes on Gaza’s largest refugee camp that killed scores of people in attacks that Israel said targeted a Hamas commander.

“This is just the latest atrocity to befall the people of Gaza where the fighting has entered an even more terrifying phase, with increasingly dreadful humanitarian consequences,” Martin Griffiths, the UN humanitarian chief, said in a statement.

He said “the world seems unable, or unwilling, to act,” adding that “this cannot go on. We need a step change.”