The U.N. secretary-general said in a statement Saturday that he was "gravely concerned" about the escalation of violence in Gaza and southern Israel.
"I call on Hamas and other Palestinian militants to cease the launching of rockets and incendiary kites and provocations along the fence," Antonio Guterres said. "And Israel must exercise restraint to avoid further inflaming the situation."
Guterres said any further escalation of tensions would endanger lives, deepen the "humanitarian catastrophe" in Gaza and undermine support for the return of the Palestinian Authority to the territory.
Guterres' statement came hours after Hamas said international mediators had restored a cease-fire between itself and Israel.
"With Egyptian and U.N. efforts, we reached [an agreement] to return to the previous state of calm between the [Israeli] occupation and the Palestinian factions," Hamas spokesman Fawzi Barhoum said.
But Israel did not confirm the cease-fire.
On Saturday morning, an Israeli tank fired on a Hamas post in Gaza after Palestinians attempted to breach the border. There were no reports of fatalities.
Friday, an Israeli soldier was shot dead and four Palestinians were killed along the volatile Gaza border.
The soldier was the first member of the Israeli army to be killed on the Gaza front since the 2014 war between Israel and Hamas.
In retaliation, Israeli jets and tanks targeted at least 60 Hamas sites Friday.