GAZA CITY, Gaza Strip — Israeli troops, tanks and aircraft targeted Gaza militants bombarding southern Israel with rockets and mortars Saturday, killing 50 Palestinians in the deadliest day of fighting in Gaza since Hamas seized control in June.

As many as two dozen civilians died in the fighting, including a baby and a young child. Two Israel soldiers were also killed. Gaza Health Ministry official Dr. Moaiya Hassanain said 160 people were wounded and 14 of them, including a baby, were in critical condition.

The intense fighting pushed the Palestinian death toll to more than 80 since fighting flared Wednesday. About half of those were civilians.

Palestinians leaders called the killings "genocide" and threatened to call off peace talks with Israel.

"The response to these rockets can't be that harsh and heinous," said Palestinian President Mahmoud Abbas. "It is nowadays described as a holocaust."

In Syria, exiled Hamas leader Khaled Mashaal described Israeli attacks against civilians in Gaza as "the real Holocaust."

Chief Palestinian negotiator Ahmed Qureia said Palestinian leaders including Abbas recommended suspending peace talks at a meeting Saturday in the West Bank town of Ramallah.

"I think it will be suspended," Qureia said. "What is happening in Gaza is a massacre of civilians, women and children, a collective killing, genocide," Qureia added. "We can't bear what the Israelis are doing, and what the Israelis are doing doesn't led the peace process any credibility."

Israeli officials met Saturday to discuss the Gaza violence and its implications for peacemaking. Foreign Ministry spokesman Arye Mekel said talks didn't preclude fighting. Talks are "based on the understanding that when advancing the peace process with pragmatic (Palestinian) sources, Israel will continue to fight terror that hurts its people," he said.

On Friday, Israeli Deputy Defense Minister Matan Vilnai renewed a threat to invade Gaza to crush militant rocket squads that attack southern Israel daily.

The spike in violence came just days before Secretary of State Condoleezza Rice was to arrive in the region to nudge Israel and Palestinians closer to an accord. But the rising violence could mar her visit.

Palestinian fighters kept up a steady stream of rocket and mortar attacks on Israeli targets, undeterred by Israeli troops backed by tanks and attack aircraft. Six Israelis were wounded, all but one of them slightly, in rocket fire that reached as far north as Ashkelon, 11 miles from Gaza.

The bloodletting began shortly before midnight Friday in the northern town of Beit Hanoun, where a 13-month-old girl, Malak Karfaneh, was killed by shrapnel. Hamas blamed Israel, but residents said a militant rocket fell short and landed near the baby's house.

Before dawn Saturday, the battleground shifted to the town of Jebaliya and its nearby refugee camp, a center of militant activity in northern Gaza. Soldiers backed by tanks and aircraft conducted house-to-house searches and took up positions on rooftops as they clashed with militants detonating land mines and firing heavy machine guns, assault rifles and mortar rounds.

By evening, more than 40 Palestinians and two Israeli soldiers had been killed in the Jebaliya fighting.

Palestinian rocket fire earlier in the week also killed an Israeli man. On Thursday, militants raised the stakes by firing Iranian-made rockets into Ashkelon, a coastal city of 120,000 people closer to Israel's heartland.

Not all of the Gazans killed on Saturday were immediately identified, but at least 13 militants and 17 civilians died. The civilians included two unidentified children, a 17-year-old girl and her 16-year-old brother, a 45-year-old man and his 20-year-old son, and two sisters thought to be in their early 20s.

The sisters and another civilian were killed by tank shells that struck two houses in separate attacks in Jebaliya, Palestinian officials said.

The Israeli military said it was unaware of tank shells hitting houses. At one of the damaged houses, paramedics rushing an unmoving woman lying on a stretcher, her face covered with a cloth, out of a room clouded with dust.

One of the unidentified boys was killed during a series of four evening airstrikes, a medical official said.

Elsewhere in Jebaliya, a wounded man and boy lay in a gutter near a dead man. Ambulance workers took away the dead man as a youth appealed to paramedics to treat the wounded.

"Take them, they are still alive," he pleaded. Another man urged the wounded to "bear witness," or proclaim their Muslim faith before they die. The two began reciting a Muslim prayer near a boy whose lower body was ripped by shrapnel.

Tareq Dardouna, a Jebaliya resident, said a relative was killed outside his home in the crossfire that began at 3 a.m.

"His body is still on the ground," Dardouna said in a telephone interview from his home, where he was tending to four wounded people amid screaming children. "Ambulances tried to come, but they came under fire. ... We are in a real war."

Israeli government spokesman David Baker said Israel was "compelled to continue to take these defensive measures" to protect more than 200,000 Israelis living under the threat of Palestinian rocket barrages.

Militants "hide behind their own civilians, using them as human shields, while actively targeting Israeli population centers," Baker said. "They bear the responsibility for the results."

The Israeli soldiers died in the morning but publication had been held up by the Israeli military censorship until their families could be notified. Seven Israeli soldiers were wounded in the clashes, the military said.

The U.N. shuttered 37 schools it runs in northern Gaza because of the fighting, affecting some 40,000 students said Christopher Gunness, a U.N. official.

Mosques across northern Gaza and Hamas-affiliated radio appealed to civilians to stay home. Hamas closed off roads to evacuate security compounds and to keep residents away from potential airstrike targets. They also turned off street lights, apparently so militants wouldn't be seen from the air.

Hamas remained defiant.

"If (Israeli officials) decided stupidly to invade Gaza, we will fight them with God's help," Mashaal told reporters from his base in Damascus, Syria. "We will fight them like lions."

Mashaal also blamed his Fatah rivals for helping along Israel's attacks.

"I accuse the president of the Palestinian Authority of providing coverage of this holocaust in Gaza," Mashaal said in Damascus. Hamas has said Abbas' condemnation of rocket fire has given a pretext to Israel's assault on Gaza.

Journalists also came under fire in Jebaliya and a cameraman for Dubai TV, Mahmoud Ajrami, was wounded.

A health official said 35 ambulances were lying idle because they did not have fuel to power them. Israel, which supplies all of Gaza's fuel, cut back supplies in recent months in an effort to increase pressure on Hamas to rein in the rocket launchers.

Israeli-Palestinian talks resumed in November after a seven-year breakdown at a U.S.-sponsored conference. At the gathering, the two sides pledged to try to reach an accord by the end of this year. In recent weeks, negotiators have met almost daily.

But even when violence is at a lower level, Abbas' efforts are compromised by the fact that he only rules the West Bank, while Gaza is controlled by Hamas. And Israel's fragile government would be hard pressed to make concessions to the Palestinians while Gaza militants pummel southern Israel.