With the fighting raging on rooftops and streets in nearly all corners of Gaza, residents huddled in fear in their homes, hoping to keep their families safe from stray bullets and shrapnel.
Fayez Abu Taha, 45, a businessman in the southern town of Rafah, said he was trapped in his apartment building with his family after Hamas fighters took over a nearby rooftop and Fatah responded by taking over the roof of his building.
"I don't know what they are battling for now," he said. "I can see the bullets flying from my windows. Coming and going."
Maha Baraakat and her family have been trapped in their Gaza home since the fighting began. She contends that fighting is not a civil war, reports CBS News correspondent Richard Roth.
"It is a distinctly Hamas-Fatah clash going on; It's Fatah on Hamas. The citizens are staying out of this ... it's basically a fight for power," said Baraakat
Palestinian President Mahmoud Abbas of Fatah called the fighting "madness" and pleaded with Hamas' exiled leader for a halt to the violence. Abbas' forces — desperately trying to cling to their besieged bases in Gaza — lashed out at the president, saying he left them with no directions and no support in the fight.
In other developments:
Abbas and Prime Minister Ismail Haniyeh of Hamas issued a joint statement after nightfall, calling on all sides "to halt fighting, and to return to language of dialogue and respect of agreements," according to a statement from Abbas' office. The call was broadcast on Palestinian TV.
The two have made numerous calls for an end to the fighting in the past, to no avail.
Hamas radio denied the two had reached a truce agreement, and clashes increased in intensity in the hour after the statement was broadcast.
No one was listening to the elected leaders as the focus of power passed to street militias. Hamas gunmen neutralized recognized security forces linked to Fatah in frontal assaults on their strong points, ruling the streets and taking control of large parts Gaza in the process.
The rout of the security forces was so bad that 40 Palestinian security officers broke through the border fence in Rafah and fled into Egypt seeking safety, Egyptian police said.
"What I can I say? This is a fall, a collapse," said Col. Nasser Khaldi, a senior police official in Rafah.
In Washington, U.S. officials condemned the fighting. "Violence certainly does not serve the interest of the Palestinian people, and it's not going to bring the peace and prosperity that they deserve," White House spokesman Tony Snow said.