Both sides said Gaza has descended into civil war, as the death toll from two days of fighting reached 37.
Fatah, the party of Palestinian President Mahmoud Abbas, has the larger fighting force in Gaza — around 80,000 — but the more militant Hamas has a highly trained and motivated militia of 6,000 that has been overrunning some of Fatah's most strategic strongholds, reports CBS News correspondent Mark Phillips.
The conflict escalated further when the Fatah central committee decided to suspend the activities of its ministers in the government it shares with Hamas. In an emergency meeting in the West Bank city of Ramallah, the movement decided on a full withdrawal if the fighting doesn't stop, said Fatah-affiliated government spokesman Nabil Abu Rdeneh.
Tuesday's battles marked a turning point, with Hamas moving systematically to seize Fatah positions in what some in the Islamic militant group said would be a decisive phase in the yearlong power struggle. The confrontations turned increasingly brutal in recent days, with some killed execution-style in the streets, others in hospital shootouts or thrown off rooftops.
A survivor of the Hamas assault on the northern security headquarters said the Fatah forces were outgunned and that reinforcements never arrived. "We were pounded with mortar, mortar, mortar," the Fatah fighter, who only gave his first name as Amjad, said excitedly and out of breath. "They had no mercy. It was boom, boom. They had rockets that could reach almost half of the compound."
In other developments:
Battles raged across the strip Tuesday. The staccato of gunfire echoed across Gaza City, plumes of smoke rose into the air from far-flung neighborhoods and one battle sent a dozen preschoolers scrambling for cover. In one desperate attempt to boost morale, disorganized Fatah forces attacked Hamas' main TV station, but were repelled after a heavy battle.
The Hamas TV station later showed a group of captured men it said were among the attackers, blood streaming down their faces.
Early Monday, Fatah militants fired a rocket-propelled grenade at the home of Palestinian Prime Minister Ismail Haniyeh in a refugee camp next to Gaza City. The grenade blasted a hole in the wall and damaged the inside of the house, but no one was hurt.
A few hours later, Hamas militants fired at the Gaza office complex of President Mahmoud Abbas from Fatah. Abbas was in the West Bank at the time, and there were no casualties from the attack.
Many ordinary Gazans, pinned down in their homes, were furious with the combatants. "Both Fatah and Hamas are leading us to death and destruction," said Ayya Khalil, 29, whose husband serves as an intelligence officer. "The don't care about us."
In the West Bank, Abbas was meeting with Fatah movement leaders, some of whom urged him to leave the coalition government with Hamas, established three months ago, declare a state of emergency, which would give him sweeping powers, or call early elections. However, none of the options was appealing, and was likely to lead only to more turmoil.
There was concern that the 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.