Israel and the Palestinians are considering their responses to the long-delayed presentation of the so-called "roadmap" to peace in the Middle East.
Copies of the plan were delivered on Wednesday to Israeli Prime Minister Ariel Sharon, and his Palestinian counterpart Mahmoud Abbas - also known as Abu Mazen - whose appointment was a key step towards its launch.
It is intended to be a phase-by-phase route to ending conflict, and could lead to full Palestinian statehood as early as 2005.
Early on Thursday, four(CNN reports seven) Palestinians, including a two-year-old child, were killed during an incursion by Israeli troops, local officials say.
Witnesses said 10 Israeli tanks and other military vehicles, backed up by helicopters, went into the eastern part of Gaza City at dawn, and a gun battle broke out.
At least seven other people were reportedly wounded, two of them seriously, and a house was destroyed.
The Palestinians reacted with markedly more enthusiasm than Israel to the roadmap, which UN special envoy Terje Roed-Larsen said was a final plan.
"Not one comma, not one word will be changed," he told the Reuters news agency. "This is the basis of what we are going to do."
The new Palestinian Foreign Minister, Nabil Shaath, called for immediate implementation of the plan, the Associated Press news agency reported.
But Mr Sharon said in a statement he had received the blueprint "for the purpose of formulating comments on the wording," AP reported.
A bomb attack in Tel Aviv in which three people were killed by a suicide bomber failed to delay its publication.
Speaking to reporters soon after the plan was released, US President George W Bush said he was an "optimist".
He said the failure of previous similar plans was not reason to give up: "I'm an optimist. I will seize the opportunity."
He said Israel was going to have to make some sacrifices in order to move the peace process forward but no sacrifice should be made that would allow and encourage terror.
The "roadmap" was drafted by envoys from the United States, European Union, United Nations and Russia.
It calls for an immediate ceasefire, a crackdown on Palestinian militants, an Israeli withdrawal from Palestinian towns and the dismantling of Jewish settlements erected since 2001.
BBC Middle East analyst Roger Hardy says that even these initial confidence-building measures will prove difficult to implement.
President Bush said the proposals represented a starting point towards achieving the vision of two states, a secure State of Israel and a viable, peaceful, democratic Palestine.
"I urge Israelis and Palestinians to work with us and with other members of the international community, and above all directly with each other," he said in a statement read by his spokesman Ari Fleischer.
"Both Israelis and Palestinians have suffered from the terror and violence, and from the loss of hope in a better future of peace and security."
But the Palestinian militant group
Hamas rejected the "roadmap" outright.
"It is a plan to liquidate the Palestinian cause," Hamas leader Sheikh Ahmed Yassin said.
Secretary of State Colin Powell is expected to discuss the "roadmap" with both Mr Abbas and Mr Sharon next week.
The release of the plan comes hours after the new Palestinian administration took office.
In his first policy speech on Tuesday, Mr Abbas - a critics of attacks against Israelis - pledged to control militant groups and illegal weapons.
The new cabinet is the result of intense international pressure on Palestinian leader Yasser Arafat to give up some of his powers and implement democratic reforms.
Ministers include both critics of Mr Arafat and loyalists from his mainstream Fatah movement.
The US and Israel have refused to deal with Mr Arafat, who remains isolated in Ramallah by Israeli forces.
Quote:ROADMAP MAIN POINTS
Phase 1 (to May 2003): End of terrorism, normalisation of Palestinian life and Palestinian political reform; Israeli withdrawal and end of settlement activity; Palestinian elections
Phase 2: (June-Dec 2003) Creation of an independent Palestinian state; international conference and international monitoring of compliance with roadmap
Phase 3 (2004-2005): Second international conference; permanent status agreement and end of conflict; agreement on final borders, Jerusalem, refugees and settlements; Arab states to agree to peace deals with Israel
The 'roadmap': Full text