Twenty people were killed and at least 120 wounded in firefights between Hamas police and a radical Islamist sect in the southern Gaza city of Rafah, Palestinian emergency services said on Saturday.
The clashes came after radicals holed up in a mosque declared an Islamist "emirate" in the besieged Palestinian enclave.
"The clashes overnight on Friday and Saturday between Hamas and an extremist group in the southern Gaza Strip left 20 people dead and at least 120 wounded," a spokesman for the Palestinian emergency services said.
The shooting erupted Friday afternoon following weekly prayers in Rafah, which straddles the Egyptian border.
It was one of the most violent incidents in Gaza since Israel's 22-day onslaught on the impoverished enclave in December and January.
Witnesses said that following prayers, a group of Palestinians announced the formation of the Islamist "emirate," defying the authority of Hamas, which has ruled Gaza's 1.5 million people for the past two years.
"We are today proclaiming the creation of an Islamist Emirate in the Gaza Strip," Abdul Latif Musa, a representative of Jund Ansar Allah (Soldiers of the Partisans of God), said at the Bin Taymiyya mosque, the witnesses reported.
Among the dead in the clashes was Mohammed al-Shamali, head of the Hamas military unit for southern Gaza, emergency services said.
