An Al-Qaeda based group rallied in a mosque, declared rebellion against Hamas’s authority, declared that Gaza is now an Islamic Emirate.
Hamas has sent in troops to storm the mosque. 6 dead so far - 1 Hamas, 4 rebels, and a child.
BBC NEWS | Middle East | Mosque gun battle rages in Gaza
At least six people have been killed and dozens injured in a fierce gun battle in Gaza, emergency services say.
Eyewitnesses say hundreds of Hamas fighters and policemen surrounded then raided a mosque where followers of a radical Islamist cleric were holed up.
They had fired rocket-propelled grenades at the mosque in Rafah, near the Egyptian border, witnesses say.
It is thought that at least 100 supporters of the al-Qaeda-linked group Warriors of God are inside.
Hamas said a grenade fired from the mosque killed one of its fighters. The other fatalities were reported to be gunmen, and a child was also killed.
Earlier, during Friday prayers, hundreds of worshippers at Ibn-Taymiyah mosque declared Gaza an “Islamic emirate”.
The mosque’s imam - Abdel-Latif Moussa - and armed supporters swore to fight to the death rather than hand over authority of the mosque to Hamas.
The Salafi Warriors of God, or Jund Ansar Allah, gained some prominence two months ago when it staged a failed attack on a border crossing between Gaza and Israel.
The group is very critical of Hamas, which governs Gaza, accusing the Islamist group of not being Islamist enough.
Hamas has cracked down on al-Qaeda-inspired groups in the past.
It is concerned they may attract more extremist members, and has forbidden anyone except what it describes as Hamas security personnel to carry weapons in Gaza.