According to the report, the blast took place in the neighborhood's car lot.
One of the injured was seriously hurt, the sources said, and his leg will likely be amputated. Another person sustained moderate wounds and the other two were lightly injured. All the four men are in their 20s.
According to the Palestinians, international experts who visited the Strip following the Israeli offensive in Gaza warned of injuries which might be caused by the explosion of old duds.
After Operation Cast Lead, Hamas men and United Nations officials collected large amounts of duds, most of the old tank shells which did not explode, and transferred them to a special storeroom guarded by Hamas security forces.
UNWRA representatives examined the weapons, and a delegation of ammunition experts from the UN was slated to visit the Strip in order to detonate the arms in a controlled manner.
However, several days later the weapons disappeared from the storerooms, as did the Hamas security officers who were in charge of guarding them. Senior UN officials expressed their rage over the incident and demanded that the ammunition be returned.