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.
Fighting pledge
Earlier, during Friday prayers, hundreds of worshippers at Ibn-Taymiyah mosque declared Gaza an "Islamic emirate".