The official Wafa news agency reported that 19 were killed, including nine minors, after shelling a clinic run by a UN agency housing displaced persons in the northern Gaza Strip.
The facility is run by the United Nations Relief and Works Agency for Palestine Refugees in the Middle East.
According to the source, the shelling occurred in the Jabalia refugee camp, one of the areas hardest hit by Israel Defense Forces (IDF) operations.
Images released on social media showed mutilated and charred bodies.
Wafa reported that two other citizens were killed and several were wounded in a similar incident in the Bureij refugee camp in the center of the enclave.
Two civilians were also killed in Israeli attacks in the south and north of the territory, it added.
Meanwhile, medical and civil defense teams recovered 12 bodies from under the rubble in the town of Khan Yunis.
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