BEITUNIYA CHECKPOINT, West Bank - Greeted by throngs of jubilant well-wishers, 57 Palestinian prisoners got off buses Monday and kissed West Bank ground after Israel freed them in a goodwill gesture ahead of a U.S.-sponsored peace conference.

But the goodwill was tempered by Israeli plans to inaugurate a West Bank police headquarters in an area whose settlement has been blocked by the U.S., for fear it would complicate the establishment of a viable Palestinian state.

An ecstatic crowd of relatives clapped and waved Palestinian flags as the prisoners arrived at the army's Beituniya checkpoint, near the West Bank city of Ramallah, after a two-hour journey from Ketziot prison in southern Israel.

The prisoners kissed the asphalt after getting off the Israeli buses, then boarded a Palestinian bus that took them to the tomb of the late Palestinian leader Yasser Arafat, where they read from the Quran, the Muslim holy book.

Israel had been expected to free 30 other Palestinian prisoners in the Gaza Strip, but their release was delayed until Tuesday morning because Israeli President Shimon Peres did not sign off on it until late Monday.

Security officials said Israel's military chief, Lt. Gen. Gabi Ashkenazi, had objected to freeing those detainees while militants in Gaza still held an Israeli soldier who was captured in a cross-border raid in June 2006. Peres spokesman Yoram Dori refused to comment on the officials' report or discuss the delay.

Among those released in the West Bank was 66-year-old Rakad Salim, who served five years of an eight-year sentence for distributing millions of dollars from the late Iraqi President Saddam Hussein to families of Palestinian suicide bombers. Relatives and supporters held up pictures of Saddam and kissed and hugged Salim after he got off the bus.

"I feel that I am a new man, enjoying my freedom," said a smiling Salim. "This release is not enough, but we hope it is the beginning of emptying all the (Israeli) prisons."

Israel is holding around 11,000 Palestinian prisoners, whose release is a central Palestinian demand. Monday's release was the second since July, and part of Israeli Prime Minister Ehud Olmert's strategy to support moderate Palestinian President Mahmoud Abbas in his power struggle with Islamic Hamas militants who seized control of the Gaza Strip in June.

None of the Palestinians freed Monday was convicted of killing or injuring Israelis. Most of the 87 slated for release belong to Abbas' Fatah movement; none belong to Hamas.

Hamas dismissed Monday's prisoner release as insignificant.

"We congratulate the prisoners," said Mohammed al-Mudhoun a senior aid to Ismail Haniyeh, the leader of the Hamas government in Gaza. "We consider this ... a humiliation for the leadership in Ramallah that considers this humble number a great achievement."

Earlier in the day, Israeli troops shot and injured a 14-year-old who had been waiting at a Gaza crossing with hundreds of other Palestinians for their relatives to be released, Palestinian medics and witnesses said.

The Israeli troops began firing from watchtowers at the Erez crossing when the Palestinians began approaching a no man's zone separating Gaza from Israel, the witnesses said.

The military said troops opened fire at Palestinians who approached army positions at Erez and ignored warning shots. The soldiers aimed for their legs to avoid fatal injuries, the military said.

Abbas is slated to meet again with Olmert on Wednesday in Jerusalem. The two are trying to draft a joint vision of a peace deal to be presented in November at a U.S.-sponsored Mideast peace conference meant to promote a final accord between Israel and the Palestinians.

But peace efforts were undercut by Israel's announcement that it was determined to open a new West Bank police headquarters in an area east of Jerusalem where Israel plans a large-scale settlement project.

Israel's public security minister, Avi Dichter, told the Haaretz daily that police officers would move to the new building by the end of the year.

"What is planned is what will happen. We aren't talking about 'if,'" Dichter's spokesman, Yehuda Maman, told The Associated Press.

The police headquarters, already built, is in an area where Israel plans to build 3,500 homes, several hotels and an industrial park. The U.S. has blocked Israel in the past from going ahead with the project, which would cut off eastern Jerusalem, the Palestinians' hoped-for capital, from the West Bank hinterland.

Palestinian negotiator Saeb Erekat accused Israel of undermining fledgling peace efforts.