Arab countries and organizations slammed on Monday Israel for its strikes on a center for displaced Palestinians that killed dozens near the southern city of Rafah on Sunday.
The health ministry in Gaza said in a statement that the strikes "claimed the lives of 35 martyrs and left dozens injured, most of them children and women".
The Hamas-run government media office in Gaza earlier said the attack hit a center run by the UN agency for Palestinian refugees near Rafah, branding it a "horrific massacre".
The Palestinian Authority presidency in the West Bank called it a "heinous massacre", accusing Israeli forces of "deliberately targeting" the tents of displaced people.
The massacre is an act of "defiance to all international resolutions," it added in a statement.
Gaza's civil defense agency said Israeli strikes killed and wounded at least 50 people in the area, where it said 100,000 displaced people live.
Hamas said Palestinians must "rise up and march" against the attack.
The Israeli army said it had targeted Hamas fighters. Israel's army said its aircraft "struck a Hamas compound in Rafah", killing Yassin Rabia and Khaled Nagar, both senior officials for the Palestinian armed group in the occupied West Bank.
It added that it was "aware of reports indicating that as a result of the strike and fire that was ignited, several civilians in the area were harmed. The incident is under review."
Qatar said on Monday the latest Israeli attack on Rafah could hinder mediation efforts to reach a ceasefire and hostage exchange deal, a foreign ministry statement said.
Kuwait's Ministry of Foreign Affairs condemned the attack, saying the Israeli forces’ actions against Palestinians "exposes their blatant war crimes and unprecedented genocide to the whole world."
"This calls for immediate and firm intervention by the international community to compel these forces into adhering to international legitimacy resolutions, including the International Justice Court resolution on immediately ceasing the aggression against Rafah, and protecting the Palestinian people," it demanded in a statement.
Egypt strongly condemned the attack, saying Israeli forces "deliberately" targeted the displaced.
The Foreign Ministry said Cairo had called on Israel "to meet its legal commitments as an occupying power" and respect the International Court of Justice’s call on it to immediately cease its military operations.
The Jordanian Foreign Ministry condemned the "ongoing heinous war crimes committed by the Israeli forces in Gaza," saying the latest attack in Rafah was a "flagrant challenge to the ICJ and grave violation of international law and international humanitarian law."
The Arab Parliament echoed the condemnation, warning in a statement that "failure to hold Israel to account for its crimes and massacres against the Palestinians and failure to take any deterrent measures against it will only make it commit more killings and cause more destruction."
The Organization of Islamic Cooperation slammed the "heinous Israeli massacre against Palestinian civilians," describing it as a "war crime, crime against humanity and state organized terrorism" and demanding that Israel be held to account before international justice.