Israeli forces killed seven Palestinian militants in a clash before dawn Wednesday, pressing its war against armed groups in the Gaza Strip days before President Bush arrives to promote Israeli-Palestinian peace.

Bush has no plans to visit Gaza, which is controlled by the Islamic militant group Hamas. But persistent violence in the area could overshadow his visit, his first to the region as president.

The visit is part of Bush's intense efforts to get Israel and the Palestinians to sign a peace agreement by the time he leaves office in January 2009.

Bush is expected to meet jointly with Israeli Prime Minister Ehud Olmert and Palestinian President Mahmoud Abbas, Palestinian officials said on condition of anonymity due to the diplomatic nature of the matter. Olmert's office would not confirm the news.

Israel is pursuing peace with Abbas' Western-backed government, which rules from the West Bank and is locked in a power struggle against Gaza's Hamas rulers. Hamas, which seized control of Gaza last June after routing Abbas' forces there, opposes the peace talks.

While embracing Abbas, Israel frequently conducts military operations against militants in Gaza in response to frequent rocket attacks launched from the area.

In Wednesday's violence, Israeli troops killed seven militants, including at least three Hamas members, in an operation east of Gaza City, Hamas and Palestinian medical officials said. Five gunmen were wounded, Hamas said. The body of the seventh militant, killed overnight, was turned over to Palestinian medics by Israel. The military said he was killed while trying to infiltrate into Israel.

The Israeli army confirmed that ground troops and Israeli aircraft fired at gunmen who had shot anti-tank missiles toward the soldiers. Israel has killed dozens of militants in similar pinpoint operations in recent weeks.

Hamas vowed revenge. "This is part of the ongoing conspiracy against the resistance. Resistance is not going to stop," said Hamas spokesman Ismail Radwan.

Abbas spokesman Nabil Abu Rdeneh denounced the Israeli raid as an "aggressive act that aims to escalate the situation prior to the visit of President Bush, to try to impose a security agenda on the visit and evade implementing political commitments."

Israeli Defense Minister Ehud Barak said Israel is trying to avoid a large military operation into Gaza, but that there may be no choice to stop the firing of crude "Qassam" rockets.

"We will provide the answer to the Qassam," Barak told Israel Radio. "We are not drifting toward the big operation but we will also not refrain from it if and when it becomes necessary."

Israeli defense officials are wary of such a broad campaign, fearing heavy casualties of Palestinian civilians and Israeli soldiers. Security officials said that for diplomatic reasons, a broad operation is unlikely before Bush's visit.

Barak said the limited Israeli operations in Gaza had killed 60 Palestinian militants in the past month, and a total of 200 in all of 2007.

Israel's internal security service, Shin Bet, said 13 Israelis died in violence in 2007, the lowest number since Palestinians launched their uprising in 2000. The number of Palestinian attacks in 2007 also reached a seven-year low at 2,946. There was just one suicide bombing — a January attack that killed three Israelis.

The Shin Bet attributed the drop both to an improvement in the performance of Israel's security services and to a dip in the motivation of Palestinian militants. Twenty-nine suicide bombings were thwarted at the last moment in 2007, the agency said.

Rocket attacks from Gaza dropped to 1,296 last year from 1,722 in 2006. But mortar fire from the strip jumped dramatically from 55 in 2006 to 1,511 last year.

At the Rafah crossing in Gaza, meanwhile, hundreds of Palestinians began pouring in from Egypt despite Israel objections, ending a five-day standoff that left them stranded after returning from an Islamic pilgrimage to Saudi Arabia.

Green-vested Hamas representatives greeted the first two travelers to cross. A flood of returning pilgrims then walked across the border.

The pilgrims became trapped en route home last weekend when Egypt said they would have to cross through an Israeli-controlled crossing instead of going directly into Gaza through Rafah.

Israel, which considers Hamas a terrorist group, fears that some travelers are carrying large sums of money for Gaza's Hamas rulers. Fearing capture by the Israelis, Hamas leaders among the pilgrims refused to go through the alternate crossing.

An Egyptian official said Israel had been informed of Egypt's decision to let the pilgrims back, but Israeli Foreign Ministry officials said they had not been told.

Israeli defense officials said Israel had not approved the pilgrims' return and that Egypt's decision "contradicts understandings" between the two countries. The Israeli officials spoke on condition of anonymity because they were not authorized to speak to the media.

Olmert and Abbas relaunched peace talks in late November at a summit in Annapolis, Md., but negotiations have had a rocky start.

The Palestinians are upset over Israeli construction in the West Bank and east Jerusalem_ areas captured by Israel in the 1967 Mideast war and claimed by the Palestinians for a future independent state. Israel, meanwhile, is furious over the death of two Israeli hikers who were gunned down in the West Bank on Dec. 28.

Israeli security officials said late Tuesday that two Palestinian gunmen involved in the killing were members of Abbas' Fatah, and one of them was a member of Abbas' security forces. The statement said the two turned themselves in to Palestinian police to avoid arrest by Israeli forces.

Barak said Israel would be watching the Palestinian actions against the attackers closely and he hopes they "rot in jail until their dying days." If they are let out of jail, Israel will track them down, he said.

Olmert met Barak and Foreign Minister Tzipi Livni on Wednesday, government officials said. Army Radio said they would discuss the involvement of Fatah members in the attack.

Israel has repeatedly said progress in peace talks would hinge on Abbas' ability to rein in militants and reform what has been a corrupt and undisciplined security force.

In Ramallah, meanwhile, prominent West Bank leaders of Fatah shaved their heads to demonstrate solidarity with an activist shaved by Hamas forces in the Gaza Strip.

Fatah said Hamas forces rounded up a group of Fatah leaders, and shaved off half of one man's hair and mustache to humiliate him. Hamas denied it shaved the man.