Dozens of Palestinians have been killed in two separate incidents, according to Gaza officials, after Israeli forces opened fire, the Israeli military said.

Twenty-seven people were killed in southern Gaza on Tuesday as Israeli troops opened fire near a US-backed aid centre, with the military saying the incident was under investigation.United Nations chief Antonio Guterres decried the deaths of Palestinians seeking food aid as "unacceptable" and the UN rights chief condemned attacks on civilians as "a war crime",

Gaza's Hamas-run health ministry said more than two dozen Palestinians were killed and scores injured early Tuesday near an aid hub run by the U.S.-backed Gaza Humanitarian Foundation.