Gaza is "fast becoming a graveyard for children", the secretary-general of the United Nations (UN) has warned.

Speaking on Monday, António Guterres warned that the situation in the enclave "more than a humanitarian crisis, it is a crisis of humanity".

"Hundreds of girls and boys are reportedly being killed or injured every day," Guterres told a news conference, on the eve of the first full month since Hamas launched its attack on Israel, and the Israeli military responded with retaliatory strikes.

Guterres again called for an immediate ceasefire.

His remarks were criticised by Israeli Foreign Minister Eli Cohen, who wrote "shame on you" on X - formerly known as Twitter - tagging the UN boss in the post.

"More than 30 minors - among them a 9 month-old baby as well as toddlers and children who witnessed their parents being murdered in cold blood - are being held against their will in the Gaza Strip," he said, adding:

Quote Message: Hamas is the problem in Gaza, not Israel's actions to eliminate this terrorist organisation."

Hamas is the problem in Gaza, not Israel's actions to eliminate this terrorist organisation."

As the fighting enters its fifth week, it shows no sign of easing, with the latest figures from Gaza's Hamas-run health ministry suggesting 10,022 people have now been killed in the enclave - including 4,104 children - since Israel's campaign began. Israel began bombing Gaza after Hamas killed more than 1,400 people in Israel and kidnapped more than 200 others.