Also Thursday, Israeli troops deepened their three-day-old offensive in a Gaza Strip refugee camp, killing eight Palestinians, most of them armed, and demolishing several buildings. In the West Bank, three Palestinians, including a 13-year-old boy, were killed by army fire.
Israeli officials expressed disappointment that the U.S. did not use its veto on Wednesday's United Nations Security Council resolution condemning the loss of life and Israel's demolition of homes, reports CBS News Correspondent Robert Berger. The United States abstained, the first time in nearly two years it did not exercise its veto on a resolution sharply critical of Israel.
The international condemnation came after a deadly tank attack that killed eight Palestinian protesters, most of them children, on Wednesday. Israel apologized for the shooting, which also left 50 people wounded.
Officials said the U.S. should know fromthat accidents happen, and Israel does not deliberately target civilians.
Despite the U.N. action, Israel continued its operation in the Rafah refugee camp.
The Tel Aviv District Court convicted Barghouti, widely seen as a potential successor of Palestinian leader Yasser Arafat, of five counts of murder, one count of attempted murder and one count of membership in a terrorist organization. The prosecution asked the court for five consecutive life terms.
Sentencing is set for June 6.
However, the panel of three judges cleared Barghouti of responsibility for 21 other deaths, ruling there was no evidence directly connecting him to those attacks carried out by militants linked to his organization.
At the time of his arrest in April 2002, Barghouti headed Arafat's Fatah movement in the West Bank. Israel said Barghouti also played a leading role in Fatah's violent offshoot, the Al Aqsa Martyrs' Brigades, which has carried out scores of shooting and bombing attacks on Israelis during more than three years of fighting.
The court said that Arafat looked to Barghouti to carry out his wishes, including attacks, giving legal weight for the first time to the long-held Israeli government position that Arafat has been orchestrating violence.
"Yasser Arafat did not give clear and precise instructions, but he made sure that those under him understood fully when he was interested in a cease-fire and when he was interested in attacks against Israel," the ruling said.
Arafat and his aides have denied the Israeli allegations.
In response to Barghouti's conviction, Al Aqsa leaders in the Gaza Strip threatened to kidnap Israelis as a bargaining chip for their jailed leader.
Barghouti, who flashed V-signs with shackled hands as he entered the courtroom, reiterated that he does not accept the court's authority. However, the longtime advocate of a Palestinian state alongside Israel also said he believes there will be peace if Israel withdraws from the West Bank and Gaza.
"I call on the Israeli public, 'Don't believe for one moment that you can overcome the Palestinians with force,'" he said. "Palestinians have no power, but they have justice on their side."
"One day, the Palestinians will gain their liberty and freedom and Marwan, too, will be free," said Barghouti's wife Fadwa, who was not given permission to enter Israel to attend the trial.
By Thursday, the army had moved into five neighborhoods in the camp, which is home to about 90,000 Palestinians. Light exchanges of fire were reported, and Israel helicopter gunships flew overhead.
Eight Palestinians were killed Thursday when helicopters and tanks targeted groups of militants. One of the dead was a local Hamas leader who was about to plant explosives when he was killed in a missile strike.
Residents said troops demolished eight homes overnight, and said bulldozers moved into a street in the Brazil area of the camp Thursday, knocking down two homes and a shop in their path.
The army has no immediate comment. It has said it only targets homes that provide cover for weapons smuggling tunnels or gunmen.
Israel raided the refugee camp less than a week after Palestinian militants killed 13 soldiers in Gaza, seven of them along the Egyptian border.
In the West Bank, troops shot and killed three Palestinians, including a 13-year-old boy and a local Hamas leader, in separate clashes. In the incident involving the boy, the army said soldiers opened fire at someone throwing a firebomb.