Agency spokesman Mahmud Bassal said an overnight strike targeted several tents in the Al-Mawasi area of the southern city of Khan Yunis, resulting in 16 deaths.

"At least 16 martyrs, most of them women and children, and 23 others were wounded following a direct strike by two Israeli missiles on several tents housing displaced families in the Al-Mawasi area of Khan Yunis," Bassal told AFP.

Bassal also confirmed two other strikes on encampments of displaced people.

One in the northern town of Beit Lahia killed seven people sheltering in tents, while a similar attack on a tent near the Al-Mawasi area left a father and son dead, he said, adding several others were wounded in the strikes.

Separately, the civil defence agency reported two more attacks on displaced people in Jabalia -- one that killed at least seven members of the Asaliya family, and another on a school being used as a shelter that killed three.

The agency also reported two people killed by Israeli shelling in the Shujaiya neighbourhood of Gaza City.

The Israeli military did not immediately comment on the strikes, but said it was looking into the reports.

Israel resumed its military offensive on March 18, ending a two-month ceasefire with Hamas.