GAZA CITY, Gaza Strip — Israeli troops turned heavy firepower on rocket squads bombarding southern Israel on Saturday, killing 54 Palestinians in the deadliest day in Gaza since the current round of fighting erupted in 2000.
Two Israeli soldiers were killed and seven were wounded in the clashes, the military said.
The violence took a heavy toll on Gazan civilians. Moderate Palestinian leaders called the killings a "genocide" and threatened to call off peace talks.
"The response to these rockets can't be that harsh and heinous," said Palestinian President Mahmoud Abbas. "It is nowadays described as a holocaust."
The spasm of violence came days before Secretary of State Condoleezza Rice was to arrive in the region to nudge Israel and Palestinians closer to a peace accord. But the rising tensions threatened to mar her visit.
Chief Palestinian negotiator Ahmed Qureia said Palestinian leaders including Abbas recommended suspending peace talks at a meeting Saturday.
The U.N. Security Council met Saturday night behind closed doors in emergency session at the request of the Palestinians and their Arab supporters.
"We want a condemnation of the killings and we want also a call for a cease-fire by the Security Council," said the Arab League's U.N. observer, Yahya Mahmassani.
Such resolutions have failed repeatedly in the past because of U.S. and European objections that they are not balanced in their condemnation.
At least two dozen Palestinian civilians, including a baby, were among those killed Saturday, and militants said 25 fighters died. Health officials said about 200 people were wounded, 14 of them critically.
Israeli military spokeswoman Maj. Avital Leibovich called Saturday's action a "pinpoint operation" and blamed the high civilian toll on militants' practice of using homes to store and produce projectiles.
The intense fighting pushed the Palestinian death toll to more than 80 since fighting flared Wednesday. About half of those were civilians.
While expressing regret for civilian casualties, Israeli Defense Minister Ehud Barak blamed "Hamas and those firing rockets at Israel," his office said in a statement, pledging to continue the offensive to protect Israeli towns and cities.
Hamas, which is sworn to Israel's destruction, took control of Gaza by force from the rival Fatah in June.
Palestinian fighters kept up a steady stream of rocket and mortar attacks on Israeli targets, firing around 50 on Saturday alone in defiance of the Israeli assault. Six Israelis were injured by rockets that reached as far as Ashkelon, 11 miles north of Gaza.
The Israeli military said one of its airstrikes on northern Gaza targeted a parked truck loaded with 160 rockets.