GAZA CITY, Gaza (CNN) -- A radical Muslim sheikh's call for the creation of an Islamic emirate in Gaza sparked clashes with Hamas forces that left 21 people dead and injured at least 121 others.
Hamas forces blew up the home of Sheikh Abu al-Nour al-Maqdessi, leader of the radical group Jund Ansar Allah, or Soldiers of the Partisans of God, Hamas sources said.
Al-Maqdessi, also known as Abdel Latif Musa, was among the 21 dead, a hospital spokesman told CNN.
Friday's clashes were the latest between Gaza's Hamas rulers, who have said they are moderate Muslims pledged to the Palestinian cause, and more extremist Islamic groups.
Jund Ansar Allah is part of the radical Islamist movement that follows the doctrines of the "Salaf," or the predecessors -- referring to the early generations of Muslims. They reject all modern influences such as politics and government.
In a televised statement, Hamas ministry spokesman Taher Nunu called al-Maqdessi's group "outlaws" and said they have been "terrorizing the country and attacking civilians."
"We hold the group and its leader fully responsible for what is happening in Gaza and we offer our condolences to everyone who was killed during the clashes," Nunu said. "No one is above the law and we urge everyone who is a member of this group to surrender himself to the authorities or they will be accountable for all of their actions."
The gunfight erupted near a mosque in the southern Gaza city of Rafah, where the cleric delivered his sermon, the sources said. Hamas militants raided the mosque and seized control of it.
Later, the fighting spread to al-Maqdessi's home, the sources said.
Al-Maqdessi also called for a public meeting at the mosque, posting on the Jund Ansar Allah's Web site an invitation dubbed "the golden advice to the government of (Hamas leader) Ismail Haniya."
The group posted a statement on the Web site announcing the establishment of the Islamic emirate in Gaza and proclaiming al-Maqdessi "the commander of the faithful."
The statement declared that armed forces in Gaza should unite under him. It urged Muslims everywhere to support the "young emirate" by providing money, weapons and men because "this is the hope of the Muslim nation in raising the banner of monotheism in Palestine and to liberate all the lands and purify Al-Aqsa mosque from the filth of the damned Jews."
Al-Aqsa mosque is in Jerusalem.
The group accused Hamas of not being Islamic enough, saying they care more about pleasing "tyrants" than "obeying God."
But Hamas spokesman Sami Abu Zahri dismissed statements about the establishment of an Islamic emirate as "theoretical."
"It is not permitted to any party or individual to enforce their own laws because this is the responsibility of the security forces," he said.