Palestinian radicals in the Gaza Strip fired a rocket barrage into a nearby Israeli city Wednesday, killing two children and wounding 10 people, Israeli defense officials said. The rockets were launched from an area of Gaza where Israeli troops and helicopters were staging a major incursion in an attempt to stop such attacks.

One of the rockets fired at the city of Sderot slammed into an alleyway between houses, killing two Ethiopian immigrant children from an extended family, according to Israeli media reports, which identified the victims as Dorit Aniso, 2, and Yuval Abebeh, 4. Israel has a large community of Ethiopian Jews.

During the incursion, Israeli forces killed five Palestinians -- including three teenage boys -- and wounded at least 28 people, according to Palestinian medical and security officials. Israeli forces also shot and killed three Palestinians in the West Bank, the officials said.

Three more Palestinians were killed in the Jabalya refugee camp in Gaza by a missile fired from an Israeli helicopter late Wednesday night, the Reuters news agency reported. Shortly afterward, a Palestinian charity office in Gaza City was destroyed in a separate helicopter strike, which caused no casualties, witnesses said. Israel has accused the charity, which aids bereaved families and relatives of prisoners, of having links to radical groups.

Palestinian radicals and Israeli government officials trace a recent rise in Palestinian rocket and mortar attacks in the Gaza area to a plan by Israel's prime minister, Ariel Sharon, to withdraw Jewish settlers and troops from the region. Both sides say the attacks are meant to portray the Israeli army as retreating under fire and suffering a major defeat.

Israeli armored vehicles, backed by AH-64 Apache helicopter gunships, entered the Gaza Strip late Tuesday, targeting fighters who have been launching Qassam rockets, fashioned from metal pipes, toward Sderot, which is about two miles outside the border.

On Wednesday, Israeli tanks and Apache gunships fired at Palestinians armed with Kalashnikov assault rifles, anti-tank rockets and roadside bombs in skirmishes throughout the day and into the night, according to witnesses and Israeli military officials.

At 5 p.m., about an hour before Jews in Israel began celebrating the religious holiday of Sukkot, Palestinians fired three rockets at Sderot from the northern Gaza area where the Israeli forces were operating, according to Capt. Jacob Dallal, an Israeli military spokesman.

"Finding a Qassam missile is like finding a needle in a haystack," Dallal said. "For militant groups, it takes a few minutes to pull it off. They run into an open area, fire and run back into the thick of the haystack."

The Islamic Resistance Movement, known as Hamas, asserted responsibility for the attack and said it was retribution for the Israeli incursion. "Israel will react to this attack," Sharon said in a statement released by his office.

Israeli troops killed five Palestinians during Wednesday's operation. Palestinian medical officials said the victims included Saed Abu Aish, 14, and Ali Mady, 16, who they said were throwing stones at tanks. Medical officials also said they treated numerous other children for injuries.

Also killed were Tawfik Shrafi, a member of Hamas who Palestinian witnesses said was trying to lay a mine, and Mosab Baradey, from the Popular Resistance Committees, according to communiques from the two radical groups.

Mohammed Jaber, 16, died from a bullet wound as he tried to cross a road blocked by Israeli troops south of Gaza City, medical officials said.

An Israeli defense spokeswoman said troops targeted Palestinian fighters who were attacking tanks, planting explosives and trying to launch Qassam rockets. "There were also several incidents of exchanges of fire" when crowds gathered around tanks, the spokeswoman said.

Late Wednesday, more Israeli troops and armored vehicles were moving into the northern Gaza Strip, Israeli television Channel 2 reported.

Since the start of the current Palestinian uprising four years ago, Palestinians have fired about 470 Qassams and other crude rockets into Israeli communities near the Gaza Strip and at Jewish settlements inside Gaza, according to Shin Bet, the Israeli domestic intelligence agency.

The Palestinian fighters generally use fruit and olive orchards inside northern Gaza as cover when launching the rockets over the heavily fortified border.

Israeli troops have gone into the area repeatedly to try to stop the rocket attacks. The soldiers have destroyed hundreds of acres of Palestinian orchards and uprooted tens of thousands of trees there, according to the United Nations.

Correspondent John Ward Anderson contributed to this report.

A 4-year-old Ethiopian immigrant, mortally wounded by a Palestinian rocket, is moved into an Israeli hospital. Family members mourn at the funeral of Tawfik Shrafi, a Hamas member killed in Gaza by Israeli forces. Witnesses said he was trying to lay a mine.