Israel blames bombing on militants, Syria
Seven arrested by Israeli, Palestinian officials
Israeli and Palestinian officials insist the cease-fire stands.
A suicide bomber attacks a Tel Aviv nightclub.
TEL AVIV, Israel (CNN) -- As Palestinian and Israeli authorities arrested seven people in connection with the deadly bombing in Tel Aviv, accusations of blame for the killings began to focus on Palestinian Islamic Jihad and Syria.
Four Israelis were killed and at least 65 others injured in the late Friday night suicide bombing by a 22-year-old student from the northern West Bank.
Israel believes the Palestinian Islamic Jihad militant group and Syria were behind the deadly terror attack, Israel Defense Minister Shaul Mofaz said in a statement.
Syria denies any link to the suicide bombing.
Mofaz said Israel had postponed plans to transfer some Palestinian towns from its control to the Palestinian Authority. He said Israel's defense establishment needed to see Palestinian Authority President Mahmoud Abbas' government take the necessary steps against terror organizations.
Mofaz also said Israel will prevent the Islamic Jihad representative from the Palestinian territories from leaving for Cairo, Egypt, for talks between the Palestinian organizations.
The U.S. State Department considers Palestinian Islamic Jihad, which primarily operates out of Gaza, a terrorist organization. It is a militant group dedicated to the creation of an Islamic Palestinian state and the destruction of Israel, and has carried out military operations against Israeli soldiers and civilians.
Palestinian Islamic Jihad also has a presence in Syria.
Members of the militant group in the West Bank deny any involvement in the suicide bombing.
An unnamed reliable source in Palestinian Islamic Jihad told CNN on Saturday that the group's offices in Damascus, Syria, and Beirut, Lebanon, have taken responsibility for the bombing.
Israeli and Palestinian officials said the attacker was from the northern West Bank village of Deir al-Ghusun.
In a video recorded before the attack, the bomber, surrounded by flags of Palestinian Islamic Jihad, accuses the Palestinian Authority of collaborating with Israel and the United States.
Israel Defense Forces officials said Israeli soldiers later entered Deir al-Ghusun and arrested five people, including two of bomber's brothers.
Palestinian authorities said Saturday that their forces had arrested two West Bank men in connection with the bombing. Interior Minister Nasr Yousef announced the arrests after meeting with Abbas.
The blast outside The Stage nightclub in a popular beachfront area of Tel Aviv threatened to shatter a fragile cease-fire reached February 8 by Israel and the Palestinian Authority.
Abbas blamed a third party for the bombing.
"We will bring them to justice," he said. "We will not allow anyone to sabotage the ambitions of our people ... those who carried out the attack are terrorists. There is a third party which wants to sabotage this (peace) process."
Palestinian Authority Prime Minister Ahmed Qorei said: "Any kind of a military act against Israel ... is condemned and not allowed."
Rice denounces attack
U.S. Secretary of State Condoleezza Rice condemned the bombing "in the strongest possible terms" and said Palestinian leaders must take "immediate, credible steps to find those responsible."
"We understand that the Palestinian leadership has condemned the attack," she said in a statement. "We now must see actions that send a clear message that terror will not be tolerated."
Rice will travel Monday to England to attend a conference in London dealing with supporting reforms in the Palestinian Authority.
Many still hospitalized
At least 50 people injured in the blast remained hospitalized Saturday, one in critical condition, officials said.
The bomb exploded outside the club at about 11:15 p.m. Friday (4:15 p.m. ET), according to Israeli police and emergency services.
Club owner Tzahi Cohen told CNN that seven to 10 people and four security guards were waiting outside the club .
Security guards normally check patrons coming into the club, but because the club was not yet open, the people in line would not have been checked, Cohen said.
In addition to those waiting in line, people inside an adjacent store were also wounded, he said. Just before the bombing, witnesses said, security officials noticed a suspicious man heading toward the doors to the club.
The deadly attack marked the end of almost four months without a suicide bombing in Israel.
Some militant groups have said they did not consider themselves bound by the cease-fire signed February 8.
CNN's Yoav Appel, Elise Labott, Guy Raz and John Vause contributed to this report.