JERUSALEM (CNN) -- The deadly attack on a Jewish seminary in Jerusalem Thursday was planned by an operation with purported ties to Hezbollah, the Shiite militant group in Lebanon, Palestinian militant sources in Gaza said.
The information that the group Free Men of Galilee planned the attack was provided to CNN amid news reports that Hamas, the Palestinian movement that runs Gaza, claimed responsibility.
But sources within the Hamas military wing specifically denied to CNN any involvement in the attack.
Other Palestinian militant sources said Hamas leaders in the West Bank and Gaza are not claiming responsibility for the attack.
The Palestinian militant sources say the shooter was a member of Hamas but was acting on marching orders from outside Gaza and the West Bank.
Hezbollah is based in Lebanon; Hamas leader Khaled Meshaal is exiled in Syria.
The shootings killed eight students at the religious school. One of them was American, the U.S. State Department said Friday.
Another American was "severely wounded," according to State Department deputy spokesman Tom Casey.
He said the United States passed along its condolences to families, but could provide no further details because of privacy laws.
A Jerusalem police spokesman on Friday identified the shooter as Ala Abu Dehein from East Jerusalem's Jabel Mukaber neighborhood.
Police said Abu Dehein was employed as a driver and held an identity card that Israel issues to Palestinians who live in East Jerusalem.
Abu Dehein's family told The Associated Press he was the gunman. They told AP he was very religious, but was not a member of a militant group.
Abu Dehein's sister told AP he had been very upset recently over violence in Gaza. "He told me he wasn't able to sleep because of the grief," she said.
After the shootings, a general closure of the West Bank and Gaza went into effect early Friday and "will be lifted according to security assessments," a statement from Israel Defense Forces said.
Hundreds of Israelis gathered at the school Friday to mourn the students who were killed in Thursday's attack. The grief-stricken crowd spilled outside the school and onto the surrounding streets.
Hours later, the U.N. Security Council met to discuss a public statement condemning the attack as terrorism, but couldn't reach a consensus. The council said Libya -- a new, nonpermanent member -- blocked the statement.
The students, ages 15 to 26, were killed Thursday night after a gunman armed with an automatic weapon and a handgun slipped into the school and began shooting.
At least nine others were wounded before an off-duty
Israel Defense Forces officer shot the gunman dead, Jerusalem District Police commander Aharon Franko said.
A first responder told CNN that the bodies were found on the floor of the study hall surrounded by holy books.
Video from Thursday's scene showed a frantic crowd of rescue workers carrying bloodied victims into ambulances. Dozens of police officers were scouring the campus and streets around the yeshiva in case there were other gunmen.
Outside the school, scores of Israeli men gathered from surrounding neighborhoods, demanding justice for the attack.
Authorities are calling the incident at West Jerusalem's Merkaz Harav yeshiva an act of terrorism. The school is one of the largest seminaries in Israel, with about 500 students in the yeshiva and 200 in a advanced graduate program.
"Israel is at the forefront of the struggle against terrorism and will continue to defend its citizens, who are exposed to this threat on a daily basis," Israel's Foreign Ministry said in a written statement.
"Israel expects the nations of the world to support it in its war against those who murder students, women and children, by any means and with respect for neither place nor target."
Meanwhile, intense celebratory shooting took place in Gaza City after the news of the attack, with hundreds chanting and clapping in the streets. But
Palestinian Authority President Mahmoud Abbas condemned the attack.
"The Palestinian Authority condemns any attack on innocent civilians," Abbas' office said in a written statement.
The shootings came just a day after U.S. Secretary of State Condoleezza Rice, who met with both Israelis and Palestinians, announced that peace talks will resume between the two both sides.
Abbas suspended peace negotiations last week after fierce fighting broke out between Israel and Palestinian militants in Gaza. But he agreed to resume negotiations after meeting with Rice.
Israel will continue peace talks with the Palestinians regardless of the attack in Jerusalem, Foreign Ministry spokesman Aryeh Mekel said Thursday.