NEVE DEKALIM, Gaza Strip -- Thousands of masked Hamas gunmen marched in formation through abandoned Jewish settlements yesterday, firing in the air and trampling an Israeli flag in the Islamic militant group's largest military-style victory parade since the Gaza withdrawal.
The show of force -- and the Palestinian Authority's persistent failure to stop people from crossing Gaza's border into Egypt -- underscored Palestinian leader Mahmoud Abbas's trouble asserting control. Abbas pledged yesterday to seal the chaotic frontier in ''two or three days," but previous deadlines passed without change.
With elections approaching in January, Hamas and Abbas's Fatah faction are locked in an increasingly bitter power struggle. Each is trying to use Israel's Gaza pullout for political gain.
Abbas is under heavy international pressure to disarm militants, a call reiterated by Prime Minister Ariel Sharon of Israel in a speech Thursday to the United Nations.
Hamas rejects Abbas's pleas to disarm, saying its attacks drove Israel from Gaza and that armed resistance will continue.
One Hamas commander, Fathi Hamad, said the Islamic militant group will actually build up its arms.
''We will increase our production capacity and the purchase of weapons," he said.
Some 10,000 people joined yesterday's rally in the ruins of Neve Dekalim, which weeks ago was Gaza's largest Jewish settlement. People waved green Hamas flags, held posters of Hamas's founder, Sheik Ahmed Yassin, who was killed in an Israeli missile strike last year, and burned plastic foam models of settlements.
Standing in columns and wearing camouflage, the Hamas gunmen resembled a private army. Militants fired machine guns into the air, and Hamas vehicles displaying homemade rockets and grenade launchers on their roofs drove over an Israeli flag.
Ismail Haniyeh, a Hamas leader, mocked the Israeli premier's latest call for Abbas to crack down. ''We tell Sharon: 'Fool, you are asking the Palestinian Authority to do something you have failed to do with all your might,' " he said.
A delegation from Egypt's doctors' union, a group linked with the banned Muslim Brotherhood, joined the celebration, as did Magdy Hussein, a leader of another banned Islamic group, the Egyptian Labor Party.
Earlier yesterday, hundreds of masked Hamas gunmen in military-style fatigues paraded through the abandoned settlement of Netzarim.
Ziad Abu Amr, a Palestinian lawmaker in Gaza who frequently mediates between Hamas and Fatah, said he believes the Hamas threat is exaggerated. He said the militant rallies are celebrations and not meant to defy Abbas.
But Shaker Shabat, a professor at the Al Quds Open University in Gaza, said Hamas is sending two clear messages.
''The first one addressed to the Palestinian people is that Hamas is the largest military power in Gaza and it played the biggest role in kicking the occupation out," he said. ''The second is to Abu Mazen that you have to think twice before trying to disarm Hamas," Shabat said, using Abbas's nickname.