JERUSALEM (AP) – Thousands gathered Friday outside a bullet-scarred Jewish seminary in Jerusalem to mourn eight students killed by a Palestinian gunman.

Masses of mourners marched in funeral processions that began from the seminary after a rabbi recited Hebrew psalms line by line, the crowd repeating them after him in memory of the dead. Israeli officials said the victims were between ages 15 and 19 except one, who was 26.

Israel slapped a closure on the West Bank and beefed up security and emergency forces around Jerusalem and other areas in the wake of the shooting, the first major attack in Jerusalem in four years and the deadliest in Israel since a suicide bomber killed 11 people in Tel Aviv on April 17, 2006.

The attack came on the heels of a surge in fighting between Israelis and Palestinians in Gaza. More than 120 Palestinians and three Israelis died in the clashes. It was not clear who was responsible for the attack, and two Israeli television stations said security officials believed the perpetrator could have acted alone. “The investigation continues as to who was behind this terrible attack in Jerusalem,” said Israeli government spokesman Mark Regev.

The head of Hamas al-Aqsa radio retracted his station’s earlier report that Hamas took responsibility, saying that the claim was premature and based on confused information.

Abu Obeida, a spokesman for Hamas’ military wing, confirmed the group was not taking credit for the attack, at least yet.

“There may be a later announcement … But we don’t claim this honor yet,” he said.

On Thursday, a previously unknown, Lebanese-based group said it had carried out the attack, the Al-Manar satellite TV station of the Hezbollah group reported. The alleged claim by the “Martyrs of Imad Mughniyeh” after a senior Hezbollah commander killed in a car bomb last month, could not be independently confirmed.

On Friday, Israeli warplanes flew over the Lebanese capital of Beirut in a possible sign of increasing tensions following the Jerusalem shooting. Israel’s army did not comment.

Some Israeli lawmakers called on their government to break off peace talks with Palestinian President Mahmoud Abbas’ moderate, West Bank-based government, but an Israeli official said the negotiations would continue.

Israel will push ahead with talks “so as not to punish moderate Palestinians for actions by people who are not just our enemies but theirs as well,” the official said, speaking on condition of anonymity because the government had yet to make an official announcement.

The family of Alaa Abu Dheim, a 25-year-old from east Jerusalem, said he had carried out the attack on the seminary, a prestigious center of Jewish studies identified with the leadership of the Jewish settlement movement in the West Bank. They described him as intensely religious, but said he was not a member of a militant group and had planned to get married in the summer.

Abu Dheim had been transfixed in recent days by the news of bloodshed in Gaza, said his sister, Iman Abu Dheim. “He told me he wasn’t able to sleep because of the grief,” she said.

Israeli defense officials confirmed only that the gunman, who was slain, came from Jabel Mukaber in east Jerusalem, where Palestinian residents hold ID cards giving them freedom of movement in Israel, unlike Palestinians in the West Bank and Gaza.

Israeli officials identified one of the slain as 16-year-old Avraham David Moses, an American citizen whose parents moved to Israel in the 1990s.

Israeli Public Security Minister Avi Dichter told mourners that Arabs in east Jerusalem who have been involved in militant activity should be expelled to the West Bank.

Regev, Olmert’s spokesman, said that the shooting had almost certainly been organized in the West Bank. He would not confirm that Israel had reached a decision to continue peace talks, but did not deny the other official’s statement that negotiations would go on.

Police spokesman Micky Rosenfeld said the attacker walked through the Mercaz Harav yeshiva seminary’s main gate and entered the library, where witnesses said some 80 students were gathered. He carried an assault rifle and pistol, and opened fire with both weapons.

Students scrambled to flee, jumping out of windows as the gunman fired. Holy books drenched in blood littered the floor. Rosenfeld said at least six empty bullet clips were found on the floor.

David Simchon, head of the seminary, said the students had been preparing a celebration for the new month of the Jewish calendar, which includes the holiday of Purim. “We were planning to have a Purim party here tonight and instead we had a massacre,” he told Channel 2 TV. A seminary graduate who is an army officer and lives nearby rushed into the seminary with his weapon and killed the gunman, Simchon told Israel Radio. “He saw the terrorist shooting, and with amazing resourcefulness he went into one of the rooms and managed to kill him,” he said.

The seminary serves some 400 high school students and young Israeli soldiers, and many of them carry arms. Jewish seminarians gathered outside the library and screamed for revenge, shouting, “Death to Arabs,” while in Hamas-controlled Gaza thousands of Palestinians celebrated in the streets.

Abu Dheim’s family set up a mourning tent outside their home and hung green Hamas flags along with one yellow flag of the Lebanese militant group Hezbollah. Family members said several relatives had already been taken for questioning by Israeli police.

Secretary of State Condoleezza Rice, who called the attack an “act of terror and depravity,” told Abbas in a phone call Friday that she would do everything in her power to restore calm as soon as possible, said Abbas aide Nabil Abu Rdeneh, an aide to Abbas.

Abbas, who condemned the seminary attack, suspended negotiations this week because of the spike in violence in the Gaza Strip, but later backed down under pressure from U.S. Rice, who was in the region to push the talks forward.