The IDF has not yet, however, ruled out the possibility that 10-year-old Noran Deeb had been hit by Israeli gunfire.
"According to our examination, the girl apparently was not shot by Israeli army gunfire," the military spokesman's office said.
A military official, speaking on condition of anonymity, said a preliminary investigation had found a "high likelihood" that the girl was hit by Palestinian gunfire. Israel Radio quoted Israeli sources as saying that Palestinian revelers returning from Hajj pilgrimage to Mecca had been shooting into the air in the area. Residents denied the fact.
Palestinian and United Nations officials said earlier Monday that Deeb was killed by IDF gunfire as she was walking into a UN school in the southern Gaza Strip. But UN officials later said that they could not definitively identify the source of the gunfire, although all signs pointed to the Israelis.
"The only firing that took place at that time in the entire Rafah area came from the so-called Salah Adin [Saladin] IDF observation post," about 800 meters away from the school, said Johan Eriksson, a spokesman for the UN Relief and Works Agency, which administers the school.
The IDF is working with the Palestinians to carry out a joint investigation of the report, military sources said. They also said no gunfire was reported near the school, located in the Rafah refugee camp.
The army is looking into the incident and has asked the Palestinian Authority to participate in a joint investigation into the girl's death.
Doctors at Rafah hospital, where Noran Deeb was pronounced dead, said she was shot in the head.
The Palestinians also said a 7-year-old Palestinian girl was wounded in the hand.
Militants fired eight mortar shells at the Gaza settlement bloc of Gush Katif several hours after the incident, causing no injuries. The IDF said two mortars had landed in the Neveh Dekalim settlement, causing damage to one home. Hamas said the mortar fire was in response to the girl's death.
"Zionist attacks did not stop and therefore resistance will continue," said Abu Obeida, a spokesman for the Hamas military wing. "As long as the enemy does not stop, then firing of mortar bombs will continue."
In a separate event, an IDF soldier suffered light wounds when he was hit by shrapnel from a roadside bomb thrown at troops near Bethlehem. The soldier received medical attention at the site of the attack.
Also in Gaza on Monday, Palestinians opened fire on hothouses belonging to the Morag settlement in the southern Strip, and IDF troops discovered and safely defused a 50-kilogram explosive device south of Kissufim. There were no injuries in either incident.
Palestinian sources said Deeb was lining up with classmates to enter their school in the morning when she was shot by gunfire from the army's Termit post, some 900 meters away.
"I was with the other teachers outside," said the deputy principal, Mariam Abu Shamala. "The children were in line, waiting to go into their rooms. Suddenly, we heard screaming. So I ran toward the children, and saw the girl on the ground and covered with blood."
Paul McCann, a spokesman for UNRWA, confirmed Monday's shooting. "This is the fifth occasion in which children in our schools have been hurt," he said. Two girls were killed in separate shootings last fall as they sat inside their classrooms. McCann also said a student has been blinded and another wounded in the throat in recent shootings.
The incident was the second shooting in the area in two days, testing an informal cease-fire between Israel and Palestinian militants. On Sunday, IDF troops killed a 65-year-old man who entered an unauthorized area near an army post.
Monday's shooting also comes a few days after Chief of Staff Moshe Ya'alon issued new directives to the IDF suspending offensive activity in the West Bank and Gaza Strip, to enable the Palestinian Authority's security forces to deploy to combat terrorism.
On Friday, Ya'alon imposed a freeze on all offensive operations in Gaza, where Palestinians have resumed responsibility for security in areas under their control. In the West Bank, arrest operations against active terror cells will require Ya'alon's personal approval.
The Palestinians deployed thousands of police in Gaza last week in an effort to maintain calm throughout the volatile coastal area. As part of that effort, hundreds of officers took up positions in Rafah, a frequent flashpoint of fighting located along the border with Egypt, last weekend.
'''Rafah / Gaza-Streifen (Israel), 31.01.2005''' - Soldaten der israelischen Armee haben, so berichten Augenzeugen, ein zehnjähriges palästinensisches Mädchen auf einem Schulhof in Rafah im Gaza-Streifen erschossen. Ein weiteres Mädchen sei leicht verletzt worden. Nach Angaben der Armee hätte man keinerlei Kenntnisse über diesen Vorfall. Die militante palästinensische Hamas-Organisation feuerte daraufhin mehrere Granaten auf die israelischen Siedlung Newe Dekalim, in der Nähe der Stadt Rafah. Augenzeugenberichten zufolge soll hier ein Wohnhaus beschädigt worden sein, über mögliche Opfer wurde nichts bekannt.  

Der palästinensische Ministerpräsident Ahmad Qurai nannte die Geschehnisse ein „Verbrechen“ und forderte ein Ende der Gewalt. „Das ist eine schlimme Nachricht und ich appelliere an die ganze Welt, diesen Prozess am Leben zu erhalten.“

Dem israelischen Militär zufolge wird der Vorfall gemeinsam mit der palästinensischen Seite untersucht.