GAZA CITY, Gaza Strip (AP) – Fierce battles over key security positions spread to central Gaza Wednesday, with Hamas fighters wresting control of the coastal strip’s north-south road – and putting themselves in position to cut off reinforcements to beleaguered Fatah forces.

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, besides four killed there on Tuesday, Hamas said. Two other people died of wounds sustained in earlier fighting.

Violence in Gaza this week between the two factions, which nominally share power in the Palestinian Arab government, has been spiraling in the direction of all-out civil war, with more than 50 reported killed since Monday.

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 in recent weeks, smuggling weapons through tunnels under the Gaza-Egypt border.

Hamas has been systematically taking control of major positions in the north and south, apparently leaving Gaza City, the strip’s security and political nerve center, for the last.

Shops in Gaza City were shuttered on Wednesday, and streets were empty as terrified residents huddled in homes that could at any moment turn into battlegrounds, 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 food aid.

A mortar shell hit the home of a deputy Cabinet minister from Hamas in the Shati refugee camp on the outskirts of Gaza City, setting it aflame, security officials said.

On Tuesday, Hamas gunmen scored a key victory when they overran the headquarters of a Fatah-allied security force in northern Gaza. For hours, about 200 Hamas fighters fired mortars, rocket-propelled grenades and machine guns at the compound, where some 500 Fatah loyalists were holed up and returned fire.

Thirty-five jeeps full of Fatah fighters were sent as reinforcements, but never made it through Hamas roadblocks. After nightfall, Hamas seized control.

Hamas reported another strategic win on 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, which consisted of a mobile home and several shacks.

Hamas also seized control Wednesday 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 for the past year since Hamas won parliament elections, ending four decades of Fatah rule. On Tuesday, Hamas signaled it was moving into a decisive phase. It ignored pleas by Palestinian President Abbas and Egyptian mediators to honor a cease-fire and appeared to be moving ahead according to a plan.

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 previous rounds of bloodshed.

“There’s a difference between leading on the ground and leading by mobile phone,” police Colonel Nasser Khaldi said of Dahlan’s absence. “Hamas is just taking over our positions. There are no orders.”

The power struggle escalated further Tuesday when Fatah suspended the activities of its ministers in the government it shares with Hamas. In an emergency meeting in the West Bank, the movement warned it would pull out of the government if the fighting doesn’t stop, said Nabil Abu Rdeneh, an aide to Fatah’s leader, the moderate President Abbas.

There was concern that fighting might spread to the West Bank, where Fatah has the upper hand, as Hamas rang up victories in Gaza. Late Tuesday, Fatah gunmen wounded four Hamas activists in the West Bank city of Nablus, Fatah said in a statement.

In Jerusalem, Israeli Prime Minister 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 and the Consulate in Jerusalem, warning of a “very dangerous security situation” in Gaza, advised journalists not to travel there. They also urged any American journalists there to leave.

Even before the current outbreak of violence, no Western correspondents were based in Gaza. As the violence escalated this week, most reporters were staying off the streets, covering the conflict from the windows of high-rise buildings and keeping in touch with sources by telephone.