Lebanon strikes
Smoke explodes during Israeli bombing of the southern Lebanese village of Khiam amid ongoing cross-border clashes between Israeli troops and Hezbollah fighters RABIH DAHER/AFP/Getty Images

Israel and Hezbollah exchanged heavy fire across the Lebanese border Sunday, killing four combatants before they stopped one of their biggest clashes of the past 10 months.

Both sides said they aimed only at military targets, with Israel's armed forces saying a navy officer was killed in combat and two other service members were wounded.

Two Hezbollah fighters and a militant from an allied group were also killed, those groups said, according to the Associated Press.

Israel said about 100 of its jets attacked 40 sites in Lebanon in a series of preemptive strikes, Reuters reported.

Hezbollah said it responded by firing 320 rockets and sending drones to avenge last month's killing of Fouad Shukur, a commander blamed by the U.S. for the 1983 bombing that killed 241 American military personnel in Beirut.

Photos from Israel showed damage to homes in the northern port city of Acre and the village of Manot near the Lebanese border.

Following the deadly attacks, Hezbollah said the "first phase" of its retaliatory attack was over and called it a "complete success," Al Jazeera reported.

Israeli Defense Minister Yoav Gallant declared a 48-hour state of emergency and Foreign Minister Israel Katz said the country didn't want a full-scale war to erupt, according to Reuters.

But Israeli Prime Minister Benjamin Netanyahu, who said Israel shot down thousands of rockets and drones, warned that Sunday's fighting was "not the end of the story."

"Whoever hurts us — we hurt him," Netanyahu vowed on social media.

In a follow-up message, he also said Hezbollah Secretary-General Hassan Nasrallah and Iranian Supreme Leader Ali Khamenei "should know that what we did today is another step toward changing the situation in the north."

Nasrallah said during a televised address that Hezbollah's main target was an Israeli military intelligence base near Tel Aviv and that Hezbollah had launched its first drone attack from the Bekaa valley, according to Al Jazeera.

Nasrallah also said that Israel attacked about 30 minutes before Hezbollah's operation began and that the sites Israel hit had nothing to do with it.