The Lebanese radical group Hezbollah fired at least 15 mortar shells across Israel's northern border Wednesday, killing one Israeli soldier and wounding five others. The attack ended six months of relative calm along that frontier.

Israeli military officials have been predicting increased Hezbollah activity in the weeks leading up to the country's planned evacuation of 21 settlements in the Gaza Strip. The officials say that by increasing its attacks, Hezbollah hopes to both draw Israeli military resources from the evacuation and create the impression that Israel is being forced to withdraw.

Israeli troops responded to the attack Wednesday with artillery fire, and Israeli fighter aircraft struck several targets in southern Lebanon. It was unclear whether any Hezbollah fighters were killed or injured.

The fighting came as extremist Israeli settlers opposed to the evacuation plan, known as disengagement, clashed in Gaza with Palestinians and Israeli soldiers, while other protesters mounted a civil disobedience campaign in the streets of Jerusalem and other major cities.

Witnesses said several dozen settlers who have dug in near Tal Yam threw rocks at Palestinians, some of whom threw rocks back. Television footage showed the settlers, most of them in their teens and twenties, chanting "Death to Arabs." Israeli soldiers intervened to shield one Palestinian man, who was being stoned after falling to the ground. He suffered serious injury and was taken to a nearby hospital.

During morning and evening rush hours, opponents of the withdrawal filled major roads to block traffic at the entrance to Jerusalem. Some scattered oil and nails on the road, puncturing about 20 tires.

In the evening, Israeli police officers used a water cannon to disperse another crowd on the highway leading from Tel Aviv to Jerusalem. Hours later, the people congregated again, pledging to keep up the demonstrations until Prime Minister Ariel Sharon called off the evacuation plan, scheduled to begin Aug. 15. Israeli police said they arrested 150 demonstrators.

"Today was a good lesson for us," said an Israeli Foreign Ministry official, who spoke on condition of anonymity because of the sensitivity of the situation. "It has shown us that we have to be much tougher with the settlers. It's good that it happened early, with plenty of time before the disengagement."

Sharon, a longtime advocate of Israeli settlement in lands occupied in the 1967 Middle East war, has said evacuating 8,500 Israeli settlers in Gaza and about 700 more from the northern West Bank will enhance Israel's security and counter demographic trends weakening the country's Jewish majority. He has pushed the plan for more than a year, but public opinion polls show that support is dwindling as the date for withdrawal approaches.

Members of the religious wing of the settlers movement argue that it is morally wrong for Jews to abandon land they believe was deeded to them in the Bible. More secular opponents, many of whom once supported Sharon, say the evacuation sends a message of weakness to Israel's Arab enemies because it is being done without Israel having first received security guarantees or territorial concessions from the Palestinian leadership.

Israeli television news devoted much of the evening broadcast to the demonstrations. There were signs that the public was growing annoyed with the settlers' tactics. In the southern city of Beersheba, footage showed drivers who were caught in traffic as a result of the demonstrations. They were removing orange ribbons, the symbol of the anti-disengagement movement, from their cars.

Israeli soldiers evacuate a Jewish settler from a house of Palestinians that was taken over by settlers near Shirat Hayam, in the Gush Katif settlement block in Gaza. Israelis opposed to the Gaza pullout have mounted a large civil disobedience campaign in Jerusalem and elsewhere.