Gaza Pope Francis called on warring parties to put an end to violence which is wounding and killing countless children.
“Stop, please stop! I beg you with all my heart,” the pontiff pleaded in the weekly Angelus prayer.
“I think of the children, who are robbed of the hope of a dignified life, of a future. Dead children, wounded children, mutilated children, orphans, children who, for toys, have the debris of war. Children who do not know how to smile,” he said.
Hamas on Sunday belatedly accepted diplomatic calls for an extension of a humanitarian ceasefire in Gaza shortly after Israel said it was resuming its devastating military assault.
There was no immediate word on whether Israel would reciprocate, with a Hamas spokesman saying the movement had agreed to halt its fire from 1100 GMT in response to a request from the United Nations.
The move came just hours after Israel said it would no longer abide by a unilateral ceasefire which had been rejected out of hand by Hamas as unacceptable without a full withdrawal of Israeli armour from the war-torn Gaza Strip.
With the situation rapidly changing, there was no immediate indication that either side had halted their fire, with several loud explosions heard in Gaza City, an AFP correspondent said.
The renewed violence came after a rare 12-hour break in the hostilities on Saturday, which was respected by both sides, with world powers urging both Israel and Hamas to extend the temporary truce. Renewewd strikes on Sunday killed nine Palestinians on raising the overall toll from the 20-day operation to more than 1,050 with 6,000 injured.
Following a 24-hour period in which Israel held its fire, the strikes resumed at 0700 GMT on Sunday with an initial three people killed by shelling, two of them in central Gaza and a third near Khan Yunis in the south, emergency services spokesman Ashraf Al Qedra said.
Six more were killed in the following few hours, including an elderly Christian woman who was killed in an air strike on western Gaza City, which also seriously wounded her son, Al Qedra said.
Also Sunday, the army said an Israeli soldier had been killed late Saturday by mortar fire. His death, along with those of two other soldiers who succumbed to injuries sustained earlier in the week, raised to 43 the number of troops killed since the army began a major ground operation on July 17.
