The African Union chief Moussa Faki Mahamat accused Israel of a "war crime" following the deadly strike on a hospital in the Gaza strip on Tuesday.
"There are no words to fully express our condemnation of Israel's bombing of a #Gaza hospital today, killing hundreds of people," Faki said on X, formerly Twitter, calling for the international community to act.
The health ministry in the Hamas-run Palestinian territory said Israeli air strikes on the hospital compound sheltering displaced people had killed at least 200 people.
The Israeli army, however, said the rocket was misfired by Islamic Jihad Palestinian militants, an ally of Hamas.
"Targeting a hospital, considered a safe haven under International Humanitarian Law, is a war crime," Faki said.
Israel has been bombing targets in Gaza since Hamas militants from the territory attacked southern Israel on October 7, triggering a war which has left thousands of dead on both sides.
Around 3,000 people have since been killed in Israeli air strikes across the Gaza Strip.
More than 1,400 people in Israel have been killed, the majority gunned down by Hamas militants who crossed from Gaza and attacked border communities.