Jerusalem (CNN) -- Funeral services were held Friday for a 13-year-old Palestinian boy shot and killed while playing soccer in Gaza a day earlier.
A spokesman for the Gaza Health Ministry accused the Israel Defense Forces of killing the boy, identified as Ahmed Abu Daqa.
Initially, the ministry said the boy was shot in the head by an Israeli helicopter. Witnesses disputed that account Friday, saying the boy was shot in the side and the gunfire came from Israeli military vehicles.
Israeli Lt. Col. Avital Leibovich told CNN that an initial investigation by the military "did not indicate the Israeli military had any connection to the shooting." She said the military was reviewing video footage of the area and so far had not seen anybody in the area where the shooting is said to have occurred.
The incident occurred on a day marked by Israeli military activity inside Gaza and on its border with Israel.
Leibovich said that 300 meters inside Gaza, Israeli border soldiers had discovered a cache of explosives in a tunnel adjacent to a security fence.
After the soldiers returned to their post on the border and set about repairing the fence, an explosion erupted, the military said. A soldier sustained minor injuries and an unoccupied army vehicle was blown up.
Palestinian sources said that, before the boy was shot, a number of Israeli military vehicles and tanks had entered Gaza some 500 meters east of Khan Younis, where they came under fire from militants.
The tanks responded by firing two rounds towards farmland; no one was injured in that incursion, they said.
CNN's Kareem Khadder, Michael Schwartz and Talal Abu Rahman contributed to this report.