RAFAH, Gaza Strip — As a throng of Palestinians marched in protest here, an Israeli tank and helicopter gunship opened fire Wednesday, leaving several people dead, including children, and wounding dozens, Palestinian witnesses said.
The protesters were marching on neighboring Tel Sultan, a Palestinian housing project on Rafah's outskirts. There, for a second day, thousands of Palestinians were under an Israeli curfew that was enforced with sniper fire, as troops went house to house in a hunt for what the army called suspected militants.
After midnight Wednesday night, as helicopter gunships pounded the air above the rooftops, Israeli tanks and armored bulldozers pushed through two neighborhoods here. Gunshots crackled around the Rafah refugee camp, punctuated by occasional, echoing booms.
Wednesday's deadliest incident began when more than 1,000 Palestinians responded to a call to demonstrate by walking down a central avenue toward Tel Sultan.
As the leading edge of the crowd, composed of men and boys, approached an Israeli tank position, at least two thunderous explosions rang out, interspersed with jackhammer blasts of machine-gun fire.
The Israeli army expressed "deep sorrow over the loss of civilian lives" and said Wednesday that it was investigating the "very grave incident," but it said its troops did not fire deliberately on the marchers.
In a statement, the Israeli army said a helicopter had shot flares and "warning fire" of one missile toward an open area. It said that because the crowd "continued to converge toward the troops," machine guns were fired at an "abandoned structure." Four tank shells were also fired at the same building.
"It is possible that the causalities were a result of the tank fire on the abandoned structure," the statement continued, adding that this was "an area of combat" and that Palestinians had planted explosives in the road.
Palestinian witnesses angrily denied that any gunmen joined in the march. A reporter who was present but not at the front of the march saw two young men with semiautomatic rifles standing on the sidewalk at the start of the route. But he did not see any guns or other weapons among the hundreds of protesters.
At the United Nations on Wednesday, the Security Council passed a resolution critical of Israel's actions. Notably, the United States abstained rather than vetoing the measure, which is its usual reaction to resolutions against Israel.
In Washington, President Bush called on Israel to exercise restraint in Gaza. "It is essential that people respect innocent life in order for us to achieve peace," he told reporters.