The Israeli navy intercepted a ship carrying humanitarian supplies from Lebanon to the Gaza Strip and towed the vessel into port Thursday, foiling a new attempt by international activists to break Israel's blockade of the Palestinian territory.

It was the first time Israeli forces seized an aid ship, after the navy let some boats in and turned others around.

The interception was condemned by Lebanon and Syria, adding to regional tensions in the wake of last month's devastating Israeli offensive against the Islamic militants of Hamas who control Gaza.

Talks in Egypt to cement a long-term cease-fire in Gaza ran into obstacles Thursday. A Hamas delegation left Cairo without agreeing to a truce deal.

In an apparent slap at Hamas, Egyptian officials reported that security officers frisked the delegation returning to Gaza and confiscated $9.5 million to $11.5 million in dollars and euros. The cash was deposited in an account in Egypt, and the delegation was allowed to return to Gaza, a security official said. It was not clear what would happen to the money.

The Gaza fighting ended Jan. 18 when Israel and Hamas declared separate cease-fires. Some incidents of violence, notably rocket fire into Israel and Israeli airstrikes on arms-smuggling tunnels under the Gaza-Egypt border, have marred the informal truce, but Egyptian efforts to stabilize the situation appeared to be making progress.

It was unclear if the Hamas exit Thursday marked a crisis or a last-gasp push for more concessions in the group's indirect negotiations with Israel. Egypt, which is mediating, had hoped for an accord Thursday, but further talks were expected next week.

In violence late Thursday, the military said troops fatally shot a Palestinian who threw a grenade near the Gaza-Israel border. It said soldiers entered Gaza briefly to search the area.

Hamas and Israel refuse to deal directly with each other. Israel considers Hamas, which has sent dozens of suicide bombers into Israel, a terror organization. Many Hamas leaders stick to the group's ideology calling for destruction of the Jewish state, but some say they would accept a Palestinian state next to Israel.

After cementing a cease-fire, the talks' main issues are border crossings and smuggling.

Israel insists on arrangements to end Hamas weapons smuggling. It charges that the dozens of Grad rockets fired at Israeli cities during the fighting were supplied by Iran and smuggled into Gaza through the tunnels under the Egyptian border.

Hamas demands that Gaza's border crossings be reopened. "The main point revolves around us getting a clear and honest commitment to lift the blockade completely. We still didn't get that," Hamas leader Mohammed Nasr told The Associated Press in Cairo before leaving for Damascus, Syria.

Shortly after Hamas fighters overran Gaza in June 2007, expelling forces loyal to Western-backed President Mahmoud Abbas, Israel and Egypt imposed a tight blockade, allowing only humanitarian supplies in. Israel is concerned about weapons smuggling, and Egypt fears the influence of Islamic extremists.

Israeli government spokesman Mark Regev said the crossings could be opened only on the basis of a 2005 agreement that gave control to Abbas' government, with European Union monitors at the Gaza-Egypt crossing. "We would not want to see any agreement on the crossings that would give Hamas legitimacy or that would allow Hamas to enhance its power," he said Thursday.

The U.S. and other countries are considering using an international naval force to stem the flow of smuggled arms to Gaza, officials said Thursday after two days of talks in Copenhagen, Denmark.

"This is one of the tools that might be considered," said Michael Zilmer-Johns, a senior diplomat at the Danish Foreign Ministry.

The long blockade and the ensuing hardships for Gazans have spawned an effort by pro-Palestinian activists to sail ships into Gaza with supplies over the past few months.

After letting several ships from Cyprus sail into Gaza, the Israelis drew the line Thursday, banning the vessel from Lebanon.

Israeli Foreign Ministry spokesman Yigal Palmor said Lebanon does not have relations with Israel, and there was no way of knowing who or what was aboard. "This kind of provocation is unacceptable," he said.

Reporters for the Arab television stations Al-Jadeed and Al-Jazeera, who were on the vessel, said Israeli sailors fired at the ship before boarding it and beating those on board. Gunfire could be heard in the background of the telephoned reports broadcast by their stations.

The navy said no gunshots were fired aboard the ship but Israeli sailors had to overcome some resistance on the vessel. The navy towed the ship to the Israeli port of Ashdod.

Israel pledged to deliver the aid supplies to Gaza over land. Palmor said the ship would be sent home.

Late Thursday, Interior Minister Meir Sheetrit signed expulsion orders for the 18 activists who were found on the boat. Fifteen were being taken to the Lebanese border and the other three — a Briton and two citizens of India — would be sent by plane to London, Israeli officials said.

Ten activists and journalists crossed into Lebanon early Friday with the help of U.N. peacekeepers, , security officials and activists said.

Al-Jazeera correspondent Salam Khoder claimed that the ship was intercepted in Egyptian territorial waters. She said that the Israeli navy opened fire three times before about 25 soldiers boarded the ship and handcuffed the activists. She also said she was struck by the soldiers.

Among those aboard who returned early Friday was 86-year-old Greek Catholic priest Hillarion Capucci, who while archbishop in Jerusalem was convicted by an Israeli court in 1974 of using his diplomatic status to smuggle arms to Palestinian militants. He was later freed at the intervention of the Vatican and deported.

The organizers of the ship's voyage, Lebanese political and human rights activists, said 18 people were on board and the cargo included medicine, food, toys and basic humanitarian supplies such as mattresses and blankets. An Israeli officer told Army Radio that no weapons were found.

Lebanon's prime minister, Fuad Saniora, condemned the seizure as a "blatant attack." A Syrian Foreign Ministry statement sharply criticized what it called Israel's act of "maritime piracy."