At least three Palestinians were killed on Monday during a gun battle between members of the rival Hamas and Fatah groups in the Gaza Strip. It was the most serious internal Palestinian violence to erupt since Hamas, an Islamic militant group dedicated to Israel's destruction, defeated the long-dominant Fatah faction in a January election and formed a government.Medics said three gunmen, two from Fatah and one from Hamas, were killed in the fighting near the town of Khan Younis and several other participants in the battle were wounded. The clash broke out after Hamas accused Fatah of having kidnapped three of its members, security officials said. Last month, 20 people were wounded in fighting between Hamas and Fatah supporters in Gaza after exiled Hamas leader Khaled Meshaal condemned President Mahmoud Abbas's veto of a new security force, formed by Hamas and headed by a top militant.