JERUSALEM, Dec. 29 (JTA) — Israeli and Palestinian leaders appeared to be less optimistic this week about quickly resolving outstanding issues that have precluded an agreement on Hebron. Hopes for an agreement were raised last week after Prime Minister Benjamin Netanyahu and Palestinian Authority leader Yasser Arafat met to discuss the redeployment of Israeli troops from most of the West Bank town. But an accord on the redeployment and the transfer of Hebron to Palestinian self-rule was not expected before the return to the region early this week of U.S. Middle East envoy Dennis Ross, whose mediation efforts had re-energized the Hebron talks. In anticipation of Ross’ return, Arafat met Sunday night with Israeli Defense Minister Yitzhak Mordechai at the Israel-Gaza border to discuss security issues. Earlier, Arafat was quoted as telling Egyptian leaders in Cairo that difficult issues remained unresolved, including Israeli pursuit of suspected terrorists into self-rule areas, buffer zones around Hebron’s Jewish quarter and a timetable for the permanent-status negotiations that are expected to resume after a Hebron deal is concluded. Meanwhile, Netanyahu declared Sunday that the Jewish state alone would continue to maintain security at the Tomb of the Patriarchs, the holy site that is sacred to both Jews and Muslims and is at the center of the struggle over Hebron. Arafat has insisted on joint Israeli-Palestinian patrols at the tomb. In Jerusalem, Israeli and Palestinian negotiating teams continued talks at the Laromme Hotel on civilian issues. Jamil Tarifi, the head of the Palestinian negotiating team on civilian affairs, said some understandings had been reached, but an accord still had to be drafted. As the negotiations continued, tensions remained high in Hebron, where about 450 Jewish settlers live among 130,000 Palestinians. Police were investigating an unexplained explosion Sunday near the Avraham Aveini complex in the Jewish quarter. No one was injured and there was no damage. Later in the day, a car belonging to a Palestinian official was set on fire at the site of the blast. Some 2,000 right-wing activists spent the weekend in Hebron, in a show of solidarity with the Jewish community there. Meanwhile, a delegation of left-wing activists led by the son of slain Prime Minister Yitzhak Rabin met with Hebron rabbis and Jewish community leaders to discuss cooperation against violence. “The purpose of this meeting is to learn from the past,” Yuval Rabin told reporters. “We are facing an important test, and I would like to issue a clear call that no one has permission to act in a violent way against the political processes we are facing.” In another development, classes resumed Saturday at the Islamic University in Hebron. Israel had closed the campus 10 months ago, after a series of suicide bombings. Security forces had suspected that Islamic militants were active around the campus. The Israel Defense Force spokesman said the army agreed on reopening the school after receiving commitments from the university’s administration to maintain order.