( AP ) - Fierce battles over key security positions spread Wednesday to central Gaza, with Hamas fighters wresting control of the coastal strip's main north-south road - and putting themselves in position to cut off reinforcements to beleaguered Fatah forces.
Hamas leaders blamed the Gaza fighting on President Mahmoud Abbas, saying his security forces were corrupt and riddled with criminals. Abbas, of Fatah, called the fighting "madness" and appealed to Hamas' exiled leader, Khaled Mashaal, to end the violence.
Gunmen also fought for control of high-rise buildings in Gaza City that serve as sniper positions. Six militants died in clashes near the besieged house of a senior Fatah commander in Gaza City, in addition to four killed there Tuesday, Hamas said. Two other people died of wounds sustained in earlier fighting.
A mortar shell hit the home of a deputy Cabinet minister from Hamas in the nearby Shati refugee camp, setting it aflame, security officials said. No one was hurt, and the official was not at home, officials said.
Violence in Gaza between the two factions, which nominally share power in the Palestinian government, has rapidly spiraled toward all-out civil war, with more than 50 reported killed since Monday. Hamas has systematically taken control of security positions in the north and south, apparently leaving the main battle for the strip's security and political nerve center in Gaza City for last.
An announcer on a Hamas radio station said the offensive would proceed to the presidential compound and the national security headquarters in Gaza City.
Hamas demanded Fatah-allied security forces in the north relinquish their weapons by 7 p.m. (noon EDT) Friday, or risk having them taken by force. The ultimatum was delivered in text messages and radio announcements.
Shops in Gaza City were closed and streets were mostly empty as terrified residents huddled in homes. The U.N. Relief and Works Agency announced it couldn't distribute food to the 30 percent of the Gaza Strip that relies on international aid.
Abbas urged an end to the bloody confrontations. He spoke by phone with the Damascus-based Mashaal to try to stop the crisis, said Abbas aide, Nimr Hamad.
"This is madness, the madness that is going on in Gaza now," Abbas told reporters.
Hamas spokesman Sami Abu Zuhri, said the clashes could have been avoided if Abbas had given the Hamas-led Cabinet control over the security forces, which he blamed for a wave of kidnappings, torture and violence in Gaza.
"'The president bears complete responsibility for the current crisis," he said. "Because of the president's hesitations and his inability to move to deal with the issues, we had to take this step. This could have been avoided with only one decision from the president."
The mounting bloodshed touched off protests in two main Gaza towns.
Several hundred tribal leaders, women, children and Islamic Jihad militants turned out in Gaza City for a protest initiated by Egyptian mediators. Some demonstrators scattered after masked Hamas gunmen fired in the air, but others pushed on, carrying Palestinian flags and shouting, "Do not shoot" and "national unity" over a loudspeaker.
Witnesses said Hamas gunmen shot at the protesters as they approached the house of the Bakr family - Fatah loyalists - in Gaza City, trapping the demonstrators.
Protester Bilal Qurashali said he saw a man shot in the head.
Health officials said one protester was killed and 14 others were wounded and taken to the hospital in civilian cars because ambulances couldn't navigate the heavy fire.
Separately, Hamas gunmen opened fire from a high-rise building at about 1,000 protesters in the southern town of Khan Younis, wounding one and breaking up the protest. A Fatah-affiliated officer was shot to death at the National Security compound in the town.
Confrontations have turned increasingly brutal in recent days, with some killed execution-style in the streets, others in hospital shootouts or thrown off rooftops. Both sides have been arming themselves by smuggling weapons through tunnels under the Gaza-Egypt border.
On Tuesday, Hamas gunmen scored a key victory when they overran the headquarters of a Fatah-allied security force in northern Gaza.
Hamas reported another strategic win Wednesday, saying it seized a Fatah post on the main north-south road, where security forces often stopped cars carrying Hamas loyalists. Hamas said it brought a bulldozer to flatten the post, made up of a mobile home and several shacks.
Hamas also seized control of a Fatah post on Gaza's coastal road - another main artery for reinforcing Fatah troops.
Hamas and Fatah have waged a power struggle in fits and spurts since Hamas won parliament elections last year, ending four decades of Fatah rule. On Tuesday, Hamas ignored pleas by Abbas and exasperated Egyptian mediators to honor a cease-fire, and appeared to be moving ahead according to a plan.
Abu Zuhri said Hamas did not intend to stop the fighting.
"We are going ahead with the steps we have taken in confronting all the security posts and to clear the security posts," he said.
In contrast, Fatah commanders complained they were not given clear orders by Abbas to fight back and that they had no central command. Fatah's strongman in Gaza, Mohammed Dahlan, has spent the last few weeks in Cairo for treatment of a knee injury. Other leading Fatah officials left Gaza for the West Bank after earlier bloodshed.
"There's a difference between leading on the ground and leading by mobile phone," police Col. Nasser Khaldi said of Dahlan's absence. "Hamas is just taking over our positions. There are no orders."
The power struggle escalated Tuesday when Fatah suspended the activities of its ministers in the coalition government and warned it would pull out of the government if the fighting doesn't stop.
There was concern that fighting might spread to the West Bank, where Fatah has the upper hand.
Late Tuesday, Fatah gunmen wounded four Hamas activists in the West Bank city of Nablus, Fatah said. On Wednesday, unidentified gunmen opened fire at a Hamas school in the West Bank city of Ramallah, security officials said. No one was injured.
Israeli Prime Minister Ehud Olmert proposed stationing international forces along the Gaza Strip's volatile border with Egypt to prevent arms from reaching Palestinian militants, including Hamas. However, he ruled out assistance to Abbas' forces.
The State Department, warning of a "very dangerous security situation" in Gaza, advised journalists not to travel there and urged U.S. journalists there to leave.