Islamic radicals from an al-Qaida-inspired group battled Hamas security in the Gaza Strip in shootouts that killed at least 13 people.
The fighting began when Hamas forces surrounded a mosque in the southern Gaza town of Rafah where about 100 members of Jund Ansar Allah, or the Soldiers of the Companions of God, were holed up, including some armed with suicide belts and rifles, according to residents of the area.
The confrontation was triggered when the leader of the group defied Gaza's Hamas rulers by declaring in a Friday prayer sermon that the territory was an Islamic emirate.
Jund Ansar Allah and a number of other small, shadowy radical groups seek to enforce an even stricter version of Islamic law in Gaza and have criticized Hamas for not doing so. They are also upset that the Hamas regime has honored a cease-fire with Israel for the past seven months.
Hamas has said it seeks to set an example and does not impose its views on others. It also says its violent struggle is against Israel, not the Western world. The more radical groups' calls for global Jihad undermines Hamas' attempt to appear more moderate to Western eyes.
The hard-line groups are perhaps the most serious opposition Hamas has faced since it seized control of Gaza and ousted its rivals in the Fatah movement in a five-day, bloody civil war in June 2007.