Gunfire killed at least seven people and wounded 80 today at a Fatah memorial rally for Yasser Arafat attended by more than 200,000 supporters of the defeated faction in the Hamas-ruled Gaza Strip.
A sea of yellow Fatah flags had filled a Gaza square for the biggest gathering held by Palestinian President Mahmoud Abbas's secular faction in the territory since Hamas Islamists routed its fighters there in June.
The rare Fatah rally broke up in chaos after gunfire rang out and grew into what Hamas described as battles with the rival group's fighters, forcing even members of the crowd who had initially stood their ground to bolt for cover.
Dr Muawiyah Hassanein, head of Gaza's emergency medical services, said seven people, all civilians, were killed. He said 80 people, including several Hamas security men, were wounded.
Fatah officials accused Hamas forces of opening fire from the nearby Islamic University. Hamas said its men had come under attack from Fatah gunmen and returned fire.
The emotional memorial event for Mr Arafat had given Fatah a rare chance to assemble its supporters in the Gaza Strip.
Mr Abbas, preparing for a US -hosted conference with Israel later this month on Palestinian statehood, has rejected new dialogue with Hamas until the group relinquishes control of the Gaza Strip.
Later, a Fatah official said Hamas security forces had arrested several of its activists, including Mohammad al-Nahal, a senior Fatah political leader in north Gaza.