TEL AVIV Ñ Israel's military has urged the government of Prime Minister Ariel Sharon to order a major offensive against Hizbullah.

Military sources said the General Staff has concluded that Hizbullah has embarked on a campaign of sustained tactical strikes against military and civilian targets inside Israel. The sources said the military leadership has warned the government that Israel's deterrence was being eroded against Hizbullah as well as Iran and Syria.

"We're talking about maybe 500 Hizbullah operatives in southern Lebanon," an Israeli military source said. "But they operate with impunity and we are allowing this."

On Tuesday, Hizbullah snipers killed two Israeli soldiers who were working on an antenna in their post along the Israeli border, Middle East Newsline reported. Israeli artillery and helicopters retaliated by attacking a nearby Hizbullah outpost in Lebanon and a Hizbullah operative was said to have been killed.

The sources said the General Staff wants Cabinet approval for a widescale mission in southern Lebanon that would drive Hizbullah operatives and Iranian forces from the area. They said such an operation would also track and destroy the estimated 12,000 missiles and rockets in the area.

"What is very important to understand is that a threat is emerging with Iran, Hizbullah and Syria that represents an explosive that could go off," Maj. Gen. Benny Ganz, head of Israel's Northern Command, said.

"The Hizbullah terrorist organization continues to create provocations backed by Syria and Lebanon, by means of belligerent attacks from Lebanese territory, which is a flagrant violation of Israel's sovereignty," an Israeli military statement said. "This activity comes in addition to Hizbullah's relentless attempts to incite and aid Palestinian terrorist organizations to carry out terror attacks inside Israel."

Hours after the fighting in southern Lebanon, Israeli fighter-jets flew over Beirut on late Tuesday. The flights caused sonic booms over the Lebanese capital.

The military has been preparing a range of contingencies for a major operation against Hizbullah, the sources said. They said the options include attacks on Lebanese civilian and military targets as well as installations within Syria.

"There is one address to Hizbullah Ñ and that is Syria," Israeli Health Minister Danny Naveh said.

The key challenge in any operation against Hizbullah would be to expel the Iranian presence in southern Lebanon. The sources said the Iranian Revolutionary Guard Corps's Unit 1800 has been responsible for the training and equipping of Hizbullah in southern Lebanon. They said the unit has been maintaining and operating Hizbullah's huge missile and rocket arsenal, which can strike targets north of Tel Aviv.

[On Wednesday, Israel's Cabinet was briefed by Israeli military intelligence on the leading military threats to the Jewish state. The threats were said to be Iran's nuclear weapons program and the missile arsenal of Hizbullah and Syria.]

The sources said the Sharon government, including Defense Minister Shaul Mofaz, has been uncertain in determining a response to Hizbullah attacks. They said Sharon has been concerned that a massive response would arouse the anger of the United States, which has sought a commitment from Israel against embarking on any military mission that could spark a Middle East crisis.

"We're hoping that Syria will intervene," an Israeli official said. "We don't need another military front."