A 9-year-old boy is among four people killed by Israeli forces during an incursion into the Jabalya refugee camp in the Gaza Strip.
Scores of gunmen fought a column of tanks and armoured vehicles as Israeli troops took up positions in and around the teeming camp which is militant stronghold.
The army said the operation was aimed at stopping rocket fire from the northern coastal area where the camp is situated into Israel.
Helicopter gunships fired missiles into the camp of 100,000 inhabitants as Israeli forces sealed it off in Israel's biggest incursion in the northern Gaza Strip in months.
Munir el-Deqqes (9) was shot in the chest while playing with friends outside his grandfather's house, witnesses said. "How can anyone blame children playing in the street?" said the boy's uncle. "Munir was a victim of blind Israeli retaliation."
At least 35 people, including militants and civilians, were wounded by Israeli fire, medics said.
A military source said soldiers had shot only at armed men. It was the latest chapter in Israel's military response after suicide bombers killed 16 people in southern Israel last week.
The raid marked a widening of Israel's incursion that began yesterday when forces swept in and seized control following a barrage of makeshift rocket strikes in southern Israel.