The Israeli military was investigating whether a teenage Palestinian girl killed in the Gaza Strip was hit by a Palestinian or an Israeli mortar shell, an army spokeswoman said on Friday, Reuters reported.
"We are running through the checking procedures and checking all the evidence in the case," the spokeswoman said.
The girl was killed by a shell that exploded in the Hamas-ruled Gaza Strip on Thursday.
Israeli military officials said an initial investigation showed she was probably killed by a misfired mortar launched by Palestinian militants during clashes with soldiers near a border crossing in the area.
A Palestinian doctor who examined fragments from the body told Reuters he could not identify their source.
Palestinian hospital workers said three other people were wounded when the shell struck near a house in al-Bureij refugee camp in the central Gaza Strip.
The Israel-Gaza border has remained relatively calm since Israel ended a three-week incursion into the coastal territory in January but an army spokesman said a border patrol came under fire on the Israeli side on Friday, there were no casualties.