3 Israelis, 3 Arabs Killed in Gaza and West Bank : Mideast: Incidents end relative calm that prevailed during election. Defense minister resigns after Likud’s defeat.

A brief break in intercommunal violence, coinciding with Israel’s election, ended Thursday when two Israelis who entered the troubled Gaza Strip were stabbed to death by Palestinian attackers, and undercover soldiers killed three Palestinians in a shootout in the West Bank. One plainclothes soldier also died in the clash.

The toll of six dead, the heaviest in a day this year, followed a relative calm during the Israeli vote that gave Yitzhak Rabin, the Labor Party leader who pledged to speed up peace talks, an unexpectedly large victory.

Shootings and knifings have become the main feature of the struggle over the West Bank and Gaza Strip, largely replacing the stone-throwing by Palestinians that was once the mark of their 4 1/2-year-old uprising.

Rabin heard the news of the stabbings during a meeting with party advisers and said, “Anyone who thinks a government headed by us will not deal with terror in all its forms is making a bad mistake.”

The rival Likud Party, beaten badly in the elections, showed its first signs of post-election disarray Thursday with the resignation of Moshe Arens, the defense minister in the current government.

Arens was once considered a potential successor to Prime Minister Yitzhak Shamir, but with the defeat, his political prospects appeared weak. His main strength in the party drew from his identity as a Shamir protege and not from having a large popular base.

Shamir is expected to resign from the party leadership soon, and Arens is probably saving himself from the embarrassment of being defeated in the leadership struggle.

The two Israelis were killed in a warehouse district south of the city of Gaza by four Palestinians who pretended to be vegetable buyers, police said. After the slayings, graffiti appeared on neighborhood walls claiming that the killings were the work of the Kassam force, a branch of the militant Muslim fundamentalist movement known as Hamas, and saying the killings were “a gift to the minister of pigs, Yitzhak Rabin, on the occasion of his election victory.”

In recent months, Gaza has become increasingly ghettoized as the Israeli government moved to keep large numbers of Gazans from traveling to Israel for work. The ban, gradually but only partially lifted, was in response to the May knifing of a 15-year-old girl by a Palestinian near Tel Aviv.

The majority of Gazans are unemployed, and many live in shabby refugee camps. Army patrols have been curtailed, leaving the stage to Israeli undercover units to keep some order.

In late May, a Palestinian youth stabbed and killed a rabbi near a militant Gaza settlement.

Gaza has also become a desperate backdrop to dangerous cat-and-mouse games between the undercover agents and armed groups of Muslim nationalists loyal to Hamas, which is funded by Iran. The Kassam force is preying on suspected Israeli collaborators, and the undercover units move clandestinely to hunt those who murder the collaborators.

Surveys have suggested that Israelis are prepared to divest themselves of control over the Gaza Strip. Rabin frequently told campaign audiences that his efforts for peace would focus on keeping Gazans in Gaza and out of Israeli cities such as Tel Aviv and Haifa.

The rural area around Janin has become the haven of armed Palestinians who carry out attacks on Arabs who inform for the Israeli secret police. The Palestinians, grouped into bands with names such as Black Panthers and Red Eagles, consider themselves the targets of Israeli undercover units.

The Thursday ambush took place in the town of Arrabe, a few miles from Janin. The Israelis, traveling in a car with blue plates signifying Palestinian ownership, opened fire on a group of four Palestinians, killing three; the fourth escaped.

The dead were wanted members of the Red Eagles, who are frequently affiliated with the Popular Front for the Liberation of Palestine, a Marxist faction of the Palestine Liberation Organization. The slain men were armed with a Soviet-made rifle, a fragmentation grenade and a pistol, according to authorities.

The battle between the hunters and the hunted around Janin has led to several bizarre incidents in recent months. Once, a group of undercover soldiers stormed the house of suspected Palestinian rebels. It turned out that the house belonged to a collaborator who fatally shot a soldier with his Israeli-supplied weapon, thinking the attackers were Black Panthers.

An ambush being set for nationalists by collaborators went awry when the informers opened fire on a car with blue plates carrying an Israeli undercover unit. The Israelis killed two of the collaborators.

Rabin’s meeting with advisers took place in anticipation of his being named by Israel’s ceremonial president to choose a Cabinet next week. There is much speculation as to how broad a parliamentary base Rabin will seek and whether he might even bring in a right-wing party for support.