Children were among the killed and injured by Israeli strikes on Sunday, and arrived at Nasser hospital in Khan Younis, as a fragile ceasefire in Gaza faced its first major test.

Desperate people rushed to the hospital located in southern Gaza Strip, carrying bodies, injured children and adults following a strike in Muwasi that left at least four killed.

"Damn the truce and damn life, damn this truce," said the uncle of a boy killed in the strike, while crying next to the body of the child alongside other relatives.

Israel’s military said earlier in the day its troops came under fire from Hamas militants in southern Gaza, and later said two soldiers were killed there.

The army then launched a wave of attacks and struck dozens of what it called Hamas targets.

Gaza's health officials said at least 29 Palestinians were killed across the Strip, including children.

An Israeli security official said the transfer of aid into the territory was halted “until further notice” after what it called a Hamas ceasefire violation.

The official spoke on condition of anonymity pending a formal announcement on the halt in aid, a little over a week since the start of the U.S.-proposed ceasefire aimed at ending two years of war.

A senior Egyptian official involved in the ceasefire negotiations said “round-the-clock” contacts were underway to deescalate the situation. The official spoke on condition of anonymity because he wasn’t authorized to speak to reporters.

There was no immediate U.S. comment.

Israeli Prime Minister Benjamin Netanyahu directed the military to take “strong action” against any ceasefire violations but didn't threaten to return to war.

Israel's military said militants had fired at troops in areas of Rafah city that are Israeli-controlled according to agreed-upon ceasefire lines.

Hamas, which continued to accuse Israel of multiple ceasefire violations, said communication with its remaining units in Rafah - an area under control of the Israeli army - had been cut off for months and “we are not responsible for any incidents occurring in those areas.”

Israel's military action in Gaza has killed nearly 68,000 Palestinians, according to the Health Ministry, which is part of the Hamas-run government in the territory.

A growing number of experts, including those commissioned by a U.N. body, have said Israel’s offensive amounts to genocide, an accusation Israel vehemently denies.