JERUSALEM — The Israeli military said it had launched a “wide-scale” attack on Gaza on Friday after one of its soldiers was shot dead near the border fence of the Palestinian territory, stoking fears of a new conflict.

The incident marked the first time an Israeli soldier had been killed during months of violence at the fence. More than 130 Palestinians have been killed during that period as Israel deployed snipers and sharpshooters against demonstrations, which it says are a cover for violent attacks.

The Israeli military responded with airstrikes and tank fire, saying it hit at least 15 military targets. Hamas, which controls the enclave, said three members of its military wing had been killed. The Palestinian Health Ministry in Gaza said a demonstrator also had been shot dead by Israeli forces at the fence earlier in the day.

“It was a very severe event and one we cannot tolerate,” said Israeli military spokesman Lt. Col. Jonathan Conricus.

Tensions between Israel and Hamas, which have already fought three wars, have flared in recent weeks. Efforts to broker a cease-fire have stumbled over the Palestinians’ continuing practice of launching fire-carrying kites and balloons from Gaza into Israel.

Last weekend saw the most severe bout of daytime fighting since the last Gaza war in 2014.

Conricus said that he did not have details of which Palestinian faction carried out the shooting attack but that Israel holds Hamas responsible for all attacks from Gaza. Later Friday night, rocket sirens sounded in southern Israel, and the military said it had detected at least three launches from Gaza, with two intercepted. No casualties were reported in the incident, it said.

“Everyone in Gaza needs to step back from the brink,” tweeted U.N. Middle East envoy Nickolay Mladenov, who is among those attempting to broker a cease-fire. “Not next week. Not tomorrow. Right NOW! Those who want to provoke Palestinians and Israelis into another war must not succeed.”

Israel, the United Nations and the United States all have urged economic relief for Gaza to achieve some stability. But here has been disagreement over how to do that, with concern in many quarters that aid should not bolster Hamas.

Gaza essentially has been under siege for more than a decade, with Israel imposing tight restrictions on goods and movement, and neighboring Egypt only sporadically opening its border. As friction has mounted in recent weeks, Israel has further restricted the movement of goods through Kerem Shalom, the main cargo-crossing point with Gaza.

Balousha reported from Gaza.