Gaza's ruling Hamas militant group launched a new crackdown on the rival Fatah movement early Tuesday, arresting dozens of activists and barring public gatherings after Fatah anniversary celebrations sparked deadly violence.

The fighting stretched into a second day, leaving a total of eight dead and 60 wounded, despite an unusually conciliatory speech toward Hamas by Fatah's leader, President Mahmoud Abbas.

The deaths were the first in Palestinian infighting in nearly two months. Continued clashes could undermine next week's scheduled visit to the region by President Bush, who will try to prod Israel and the Palestinians closer to peace.

Hamas has ruled Gaza with a tight grip since routing pro-Fatah forces there in June. Last week, it said it would ban large celebrations marking Fatah's 43rd anniversary.

Fireworks illuminated Gaza on Monday night, and Fatah backers fired rifles in the air, defying the ban and setting off armed clashes.

Five Palestinians died in fighting across Gaza on Monday, and a sixth died of his wounds Tuesday, medical officials said. Two others were killed in Gaza City early Tuesday in a gunbattle between Hamas security men and a family affiliated with Fatah, leaving one Hamas policeman and a Fatah supporter dead.

The eight dead included three Hamas and three Fatah supporters, officials said. Also killed were an elderly man caught in a crossfire in northern Gaza and a 14-year-old Hamas supporter shot in the southern town of Khan Younis after he left a mosque, relatives said.

The deaths were the first in Palestinian infighting since Hamas forces opened fire on a huge Fatah rally on Nov. 11, killing eight and wounding 85. That gathering was the first sign of Fatah resurgence since the Hamas takeover.

Fatah said dozens of activists were arrested overnight, and one of its leaders in Gaza City was briefly detained by Hamas forces who shaved off half his hair and mustache as humiliation. Hamas denied the charge.

Islam Shahwan, a spokesman for Hamas security forces, confirmed only that his men made a number of arrests. Hamas officials banned all Fatah celebrations, including small gatherings, on Tuesday, the actual anniversary of Fatah's founding.

Mahmoud Zahar, a senior Hamas official in Gaza, said the Gaza government "will pursue the killers and bring them to justice and punish them according to the law. We are not going to show mercy for these crimes."

After the Gaza takeover, Abbas expelled Hamas from government and installed his own pro-Western administration based in the West Bank.

In late November, he and Israeli Prime Minister Ehud Olmert relaunched peace talks in Annapolis, Md., and set a 2008 target for a peace treaty. Bush's visit is meant to bolster the fledgling peace process.

The Palestinians hope to build an independent state in the West Bank, Gaza Strip and east Jerusalem — areas captured by Israel in the 1967 Mideast war.

Olmert has signaled readiness to withdraw from a large chunk of the West Bank and part of east Jerusalem — prompting harsh criticism from within his ruling coalition. Israel withdrew from Gaza in 2005.

In an interview published Tuesday, Olmert said Israelis must understand that even their closest international allies want the country to pull back in the West Bank and share Jerusalem.

"The world that is friendly to Israel ... speaks of Israel in terms of the '67 borders. It speaks of the division of Jerusalem," Olmert told The Jerusalem Post, an English-language daily.

But Olmert said Israel would be able to hold on to some areas in the West Bank in any peace deal, with U.S. approval. Although Israel has promised to halt building in its West Bank settlements, Olmert said that didn't apply to all of them. He called Maaleh Adumim, a large settlement outside Jerusalem, an "indivisible part of Jerusalem and the state of Israel."

Palestinians reject any settlement construction, saying it compromises peace negotiations. They also want Israel to halt all construction in east Jerusalem.

Another Palestinian demand, echoed by the international community, has been that Israel ease the movement of people and goods in the West Bank, which has been severely impeded by hundreds of Israeli roadblocks.

On Tuesday, Israeli Defense Minister Ehud Barak said the roadblocks have been a proven obstacle to Palestinian attacks, and except in isolated cases, would not be dismantled.

"There is no chance of effectively fighting terror without practical daily control in the field, and the roadblocks will stay," Barak said.

Palestinian negotiator Saeb Erekat said Barak's comments were "very unfortunate."

"I don't think we can do anything about the economy of improvement of life or revival of institution-building" as long as the roadblocks remain, Erekat said.

Barak has ordered the removal of two dozen dirt embankments and two of the 16 major West Bank checkpoints since he became defense minister in June, but the Palestinians say that has not made a significant change on the ground.