More children have been reported killed in the war raging in Gaza than in four years of conflict around the world, the head of the UN agency for Palestinian refugees said Tuesday.

"Staggering. The number of children reported killed in just over 4 months in #Gaza is higher than the number of children killed in 4 years of wars around the world combined," Philippe Lazzarini said on X, formerly Twitter.

His post referenced United Nations numbers showing that 12,193 children had been killed in conflicts worldwide between 2019 and 2022.

It compared that to reports from the health ministry in Hamas-run Gaza indicating that more than 12,300 children died in the Palestinian territory between last October and the end of February.

"This war is a war on children. It is a war on their childhood and their future," Lazzarini said.

The brutal war began with the unprecedented October 7 Hamas attack that resulted in about 1,160 deaths in Israel, mostly civilians, according to an AFP count based on Israeli official figures.

The militants also took around 250 hostages, dozens of whom were released during a week-long truce in November. Israel believes about 130 captives remain in Gaza, including 32 presumed dead.

Israel's retaliatory bombardment and ground offensive have killed 31,184 Palestinians in Gaza, mostly women and children, according to the territory's health ministry.