Israeli soldiers have shot and killed three Palestinians in the Gaza Strip, including an 11-year-old child, in separate clashes. The latest casualty on Friday was a Palestinian child killed by shrapnel from an Israeli tank shell in the northern Gaza Strip, Palestinian medical sources said. Mahmud al-Qayed, 11, was hit in his chest as he was playing with a friend near the Karni crossing point between the northeastern Gaza Strip and Israel, the medical sources and witnesses said. Also, one Palestinian died after being wounded in shooting by Israeli troops near the southern village of Huzaa. Another Palestinian was killed in an exchange of fire with an Israeli army unit invading the El Moghazi refugee camp in central Gaza, Palestinian security sources said. **Helicopter fire*** The unit of a dozen armoured vehicles penetrated hundreds of metres into the sector in the Palestinian territory, accompanied by a helicopter which opened fire. Earlier, a fighter was mortally wounded by a tank shell and his body was taken to a hospital in Huzaa near Khan Yunus, the sources said. Medical sources said rescuers did not arrive for an hour as the army refused to allow ambulances through. Late on Thursday, at least three other Palestinians and a female Jewish settler were wounded in an exchange of fire in southern Gaza, Palestinian security sources said. The incident occurred when Palestinians fired five mortar shells at Gadid, a group of Jewish settlements near the town of Khan Yunus, the sources said. **PHOTO CAPTION*** A Palestinian doctor treats a wounded child in the Gaza Strip.(AFP/File/Said Khatib)