Hamas fighters have captured one of the last Gaza City bastions of forces loyal to Palestinian President Mahmoud Abbas, witnesses have said.Some of the defenders fled the heavily fortified Preventive Security headquarters. Others surrendered after they were promised "safe passage home" in an announcement on Hamas radio.Gunfire still sounded from nearby rooftops where other Fatah men were shooting at Hamas attackers, witnesses said. Medical workers said at least ten people were wounded in the battle.Fatah denied the headquarters had fallen, but green Hamas flags could be seen fluttering from its rooftop.The move is a powerful symbol to Gazans that Hamas had largely taken charge after five days of bloodshed in the territory in which more than 80 people have been killed."It's a war zone. Since yesterday we have been living the most horrible time of our life," one neighbour, Sadi, said.Hamas's seizure of the compound would deal a heavy blow to forces loyal to Western-backed President Abbas, whose aides said he was preparing a major announcement.He may well dissolve the Hamas-led "unity" government, a move that could entrench a division of Palestinian territories into two.Hamas's armed wing has made major gains in the offensive that began on Saturday, raising the prospect of an aggressive Islamist statelet of 1.5 million people on Israel's borders, beyond what Western powers have seen as the moderating influence of Mr Abbas."Gaza is lost," one senior Abbas aide has told diplomats.The violence, in which children and other civilians also have been killed, has been the bloodiest between the factions since Hamas used its Gaza power base to win a parliamentary election early last year.© Independent Television News Limited 2007. All rights reserved.