Israeli tanks rolled into a Palestinian village on the southern fringes of Jerusalem early Tuesday in response to persistent Palestinian gunfire on a nearby Israeli neighborhood.

Israel's nighttime incursion into the village of Beit Jalla was the latest in a series of violent events that stretched through the day Monday, increasing tensions in the Mideast conflict.

In the morning, Israeli helicopters in the West Bank town of Ramallah fired rockets that killed a senior PLO leader, the highest-ranking Palestinian slain in years. In the afternoon, Palestinian gunmen struck back, shooting dead an Israeli motorist in the West Bank.

On Monday night, the Palestinian militants in Beit Jalla opened fire on Gilo, a Jewish neighborhood on the far side of a valley separating the two communities. Gilo was built on land Israel captured in the 1967 Mideast war and now forms the southern edge of Jerusalem. The Palestinians want it as part of a future state.

Israeli forces shot back, and after on-and-off exchanges of fire that lasted for hours, Israeli tanks accompanied by bulldozers rumbled into the village.

In Beit Jalla, mosque loudspeakers called on people to take to the streets to resist the Israelis. A heavily Christian community, Beit Jalla has several important churches and Christian holy sites, making the Israeli entry especially sensitive.

An Israeli military statement said the operation was "limited in time" and that the army had moved in to the village after many gunfire attacks on Gilo. It said the military would try to refrain from damage to holy sites and injuries to Palestinians and foreign citizens.

Israeli forces fired flares in the nighttime sky.

The Israelis appeared to be carrying out a similar operation in the southern Gaza Strip. Israeli tanks and bulldozers moved into Palestinian-controlled territory at the Rafah refugee camp near the Egyptian border, Palestinian security sources said.

Israeli bulldozers tore down several structures, as Palestinian gunmen fired at them. Two Palestinian women were wounded by Israeli gunfire, the officials said. Palestinian gunmen and Israeli forces have frequently clashed in the area.

In several recent incursions, Israeli forces have moved in and destroyed Palestinian security buildings and outposts used by Palestinian gunmen, and then withdrawn within hours.

There was no immediate Israeli military comment on the operations in Gaza.

On Monday, the Israeli helicopters shot two missiles through the office windows of Mustafa Zibri, 63, leader of the hard-line Popular Front for the Liberation of Palestine.

Thousands of angry Palestinian protesters poured into the streets and a red-eyed Yasser Arafat declared three days of mourning for Zibri. In immediate retaliation, PFLP gunmen killed an Israeli in an ambush on a car in the West Bank.

The Palestinian Authority said in a statement that Israel was waging an "all-out war," while Israel said Zibri was involved in bombing attacks and was planning more.

Throughout 11 months of conflict, Israel has targeted Palestinians believed responsible for attacks against its soldiers and civilians, but most were considered midlevel operatives, such as bombmakers. Zibri was one of the top five figures in Arafat's PLO. The killing took place barely 200 yards from Arafat's West Bank headquarters in Ramallah.

Nabil Aburdeneh, an Arafat adviser, accused President Bush of a pro-Israeli bias that, Aburdeneh said, encouraged Israel to carry out the killing.

"This policy of assassinations which is being conducted with a green light from the United States will push the area into a new cycle of violence and danger," Aburdeneh said.

The United States has condemned the targeted killings. However, Bush has been sharply critical of Arafat, saying he could do more to rein in militants.

In the Monday morning helicopter attack, Zibri was sitting at his desk in his second-floor Ramallah apartment which doubled as PFLP headquarters. Rockets came through two windows of his corner office, decapitating Zibri and scorching the walls. No one else was hurt.

The windows of other apartments were shattered, but no one was seriously hurt.

Zibri returned to the West Bank from exile in 1999, and last year became leader of the PFLP, which has opposed the strategy of the past decade's peace talks with Israel.

According to Palestinian human rights activists, about 50 Palestinians have been killed in targeted Israeli attacks. While most were militants, the victims have included women and children who were bystanders.

Zibri was the most prominent Palestinian killed in recent years. In 1988, Israeli commandos shot and killed Khalil Al Wazir, the PLO military chief, in a raid of his Tunis, Tunisia, home. In 1995, Fathi Shakaki, leader of Islamic Jihad, was gunned down outside a Malta hotel in an attack widely attributed to Israel.

The latest violence further diminished prospects for truce talks between Arafat and Israeli Foreign Minister Shimon Peres.

"Can anybody think of negotiations now with these assassins and killers in the Israeli government?" Palestinian Information Minister Yasser Abed Rabbo said.

Eight Israelis and five Palestinians were killed over the past three days in the latest surge of violence. Since last September, 589 people on the Palestinian side have been killed, and 162 on the Israeli side.