By Nidal al-Mughrabi GAZA, June 9 (Reuters) - Fresh fighting erupted on Saturday between rival Palestinian factions in the Gaza Strip, wounding at least four people, hospital officials said. The Hamas and Fatah groups each accused the other of sparking the gunbattle in the southern town of Rafah. Hospital officials said four people were wounded, including a civilian, two Hamas gunmen and one from President Mahmoud Abbas's Fatah movement. Rafah was the scene of factional fighting on Thursday in which one man was killed, the first fatality in such a gunbattle since a truce took effect in mid-May after a wave of fighting last month claimed the lives of some 50 Palestinians. The latest clash erupted hours after Palestinian gunmen infiltrated the Israeli border in southern Gaza, sparking a gunbattle with Israeli forces which killed one Palestinian gunman. The United States is providing money for military training of members of Abbas's presidential guard and says Hamas's armed wing and executive force receive support from Iran. Fatah has asked Israel to permit a new shipment of arms and ammunition from Egypt and other Arab states to bolster its forces, and Israeli officials are considering the request. The once dominant Fatah entered a unity government in March with Hamas, victors in a parliamentary election 18 months ago, in an effort to end internal faction fighting and to help ease international sanctions imposed after Hamas took power. So far, the coalition government has failed to achieve either goal.