The massacre follows a separate assault Sunday when witnesses saw Israeli troops killed at least 31 people, also at a U.S.-backed aid distribution center, injuring over 170 others. U.N. Secretary-General António Guterres condemned Sunday’s massacre and called for an immediate and independent investigation.

Separately, The Guardian reports recent deadly airstrikes by Israel on schools sheltering displaced people in Gaza were part of a deliberate Israeli strategy that saw military planners loosen limits on strikes on places where large numbers of civilians are present. Israel has attacked six schools in recent months, killing over 120 people.