Extreme food shortages in parts of the Gaza Strip have already exceeded famine levels, and mass death is now imminent without an immediate cease-fire and surge of food to areas cut off by fighting, the world's hunger monitor has said.

The Integrated Food-Security Phase Classification (IPC), whose assessments are relied on by U.N. agencies, said Monday that 70% of people in parts of northern Gaza were suffering the most severe level of food shortage, more than triple the 20% threshold to be considered famine.