( AP ) - Hamas fighters overran one of the rival Fatah movement's most important security installations in the Gaza Strip on Thursday, and witnesses said the victors dragged vanquished gunmen from the building and executed them in the street.
The capture of the Preventive Security headquarters was a major step forward in Hamas' attempts to complete its takeover of all of Gaza.
The moderate President Mahmoud Abbas of Fatah, for the first time in five days of fierce fighting, ordered his elite presidential guard to strike back. But his forces were crumbling fast under the onslaught by the better-armed and better-disciplined Islamic fighters.
Fatah officials said seven of their fighters were shot to death in the street outside Preventive Security. A witness, Jihad Abu Ayad, said the men were being killed before their wives and children.
"They are executing them one by one," Abu Ayad said. "They are carrying one of them on their shoulders, putting him on a sand dune, turning him around and shooting."
Some of the Hamas fighters kneeled down outside the building, touching their foreheads to the ground in prayer. Others led Fatah fighters out of the building, some of them shirtless or in their underwear, holding their arms in the air. Several of the Fatah men flinched as the crack of gunfire split the air.
"We are telling our people that the past era has ended and will not return," Islam Shahawan, a spokesman for Hamas' militia, told Hamas radio. "The era of justice and Islamic rule have arrived."
Sami Abu Zuhri, a Hamas spokesman, heralded what he called " Gaza's second liberation," after Israel's 2005 evacuation of the coastal strip.
The two factions have warred sporadically since Hamas took power from Fatah last year, but never with such intensity. Hamas reluctantly brought Fatah into the coalition in March to quell an earlier round of violence, but the uneasy partnership began crumbling last month over control of the powerful security forces.
Some 80 people, most of them militants, have been killed since a spike in violence Sunday sent Gaza into civil war. At least 15 people died on Thursday.
Hospitals were operating without water, electricity and blood. Even holed up inside their homes, Gazans weren't able to escape fighting that turned apartment buildings into battlefields.
Moean Hammad, 34, said life had become a nightmare at his high-rise building near the Preventive Security headquarters.
"We spent our night in the hallway outside the apartment because the building came under crossfire in 2002," Hammad said. "We haven't had electricity for two days, and all we can hear is shooting and powerful, earthshaking explosions.
"The world is watching us dying and doing nothing to help. God help us, we feel like we are in a real-life horror movie," he said.
Shaher Hatoum, a nurse at nearby Al Quds hospital, said the facility had no electricity, water or blood, and that wounded were propped up on ward floors. Hundreds of bullets flew through windows, and fighters ignored the hospital's appeals to hold fire just long enough to have the generator and water pipes fixed, Hatoum said.
"We are waiting here for our end," Hatoum said.
The European Commission on Thursday suspended its humanitarian aid projects in the Gaza Strip, citing the escalating violence. EU humanitarian operations in both Gaza and the West Bank totaled $110 million last year. So far this year, it has earmarked $80 million.
"I fervently hope that the projects can resume very soon," EU Humanitarian Aid Commissioner Louis Michel said.
Meanwhile, Abbas was meeting in the West Bank town of Ramallah with the decision-making bodies of Fatah and the Palestine Liberation Organization. One aide, speaking on condition of anonymity because no decision had been made, said Abbas was considering pulling Fatah out of its governing coalition with Hamas.
Hamas also was training its guns at three other key command centers in Gaza City. Rocket-propelled grenades were being fired toward Abbas' Gaza compound, provoking return fire from his presidential guard.
For the first time since the fighting began, Abbas ordered his guard to go on the offensive against Hamas at the compound, and not simply maintain a defensive posture, an aide said. He spoke on condition of anonymity because the situation was fluid.
The intelligence service compound also was under siege, as Hamas fired dozens of rocket-propelled grenades in its direction.
Hamas said it was on the verge of taking over the building. But the director of the intelligence service in Gaza, Mohammed al-Masri, said in a text message that the compound was still in Fatah hands.
Mortar shells were lobbed overnight at a third key security headquarters, the National Security building.
Elsewhere in Gaza, clashes broke out at three Fatah-allied villages near the southern town of Khan Younis, but Hamas encountered little resistance as it took over security positions and homes belonging to pro-Fatah officers. A teenager was killed in the crossfire in 2002.
The violence has exposed the depths of the disarray in Fatah's ranks since Hamas ended Fatah's 40-year dominion of Palestinian politics last year.
A Hamas military victory in Gaza would split Palestinian territory into two, with the Islamic extremists controlling the coastal strip and Western-backed Fatah ruling the West Bank. Israel was watching the carnage closely, concerned the clashes might spawn attacks on its southern border.
Israeli defense officials said Wednesday that Israel, which evacuated Gaza in 2005, would not intervene unless Hamas took over Gaza and started attacking Israel.
Fatah has asked Israeli permission to bring in more arms and armored vehicles, but Tzahi Hanegbi, chairman of the Israeli parliament's Foreign Affairs and Defense Committee, told Army Radio that arming Fatah would be "insane" because the weapons would fall into Hamas hands.
He said Israel was considering backing Fatah forces in the West Bank, but did not elaborate.
U.N. Secretary-General Ban Ki-moon said he discussed the possible deployment of a multinational force in Gaza with the Security Council on Wednesday.
"We have always asked for international forces to come to the West Bank and Gaza," Abbas confidant Saeb Erekat told Israel's Army Radio. But, he added, "Honestly, on the personal level, I believe that if we don't help ourselves as Palestinians, nobody can."