JERUSALEM - Israel and the Palestinians have agreed to start drafting sections of a proposed peace accord that address the main issues of their conflict, the chief Palestinian negotiator said.

Ahmed Qureia, the veteran negotiator heading the Palestinian team, said the decision did not mean agreement had been reached on the major issues that have tormented peace talks for years: final borders, the status of disputed Jerusalem, and the fate of Palestinian refugees.

But it is the first time since negotiations resumed more than six months ago that anything will be put to paper on these divisive questions.

"We agreed with the Israelis to begin writing the positions," Qureia told reporters late Friday. He did not say what issue the two sides would start with.

Israeli government officials declined to comment.

Should negotiators agree on an issue, they will draft a single provision, Qureia said. If not, they will lay out on paper their divergent views, he added. Yesterday, he said that negotiations were "going through a difficult period" because of tense discussions on Jerusalem and Palestinian refugees.

Israel and the Palestinians resumed peace talks in November at a U.S.-sponsored conference in Annapolis, Md. Continued Israeli settlement construction and Israeli security concerns have clouded negotiations, and both sides have expressed doubt about achieving the declared goal of finalizing an accord by the end of the year.

Secretary of State Condoleezza Rice is headed to the region this week in an effort to push negotiations forward.

In Gaza yesterday, the Islamic militant group Hamas claimed responsibility for a string of attacks in Israel carried out several years ago.

A Hamas Web site listed nine attacks that killed 26 people, most of them Israelis, from 2002 until 2005, and said all the attackers came from the West Bank. Other Palestinian groups claimed responsibility for some of those attacks when they happened, though it is possible they were joint operations.

Hamas said it kept quiet about its role in the attacks until now for security reasons.

In related news, the Israeli military said the West Bank and Gaza Strip would be sealed at midnight for the Jewish Shavuot holiday, which begins at sundown today. Holiday closures, which bar nearly all Palestinians from entering Israel, are a routine part of an effort to minimize the possibility of a Palestinian attack. The closure is to last until midnight tomorrow.