Undercover Israeli security forces shot and killed five Palestinian members of a militant organization and an 18-year-old bystander at a restaurant Sunday night in the West Bank city of Tulkarm, about 20 miles northeast of Tel Aviv, according to Palestinian security forces.

Fifteen members of the al-Aqsa Martyrs Brigades, an armed group affiliated with Palestinian leader Yasser Arafat's mainstream Fatah political movement, were eating dinner inside the restaurant or standing guard outside when undercover troops in a white Volkswagen opened fire, hitting six Palestinian men in the head and injuring at least one other in the leg as he fled, Palestinian security officials said.

An Israeli military spokeswoman said that "six gunmen," including a senior al-Aqsa leader in the city, were killed in the attack at 8:30 p.m. It could not be learned whether the Palestinians returned fire.

The attack resulted in the highest number of Palestinian fatalities in the West Bank in recent weeks as Israeli soldiers, border police and other security agencies have conducted continual raids against armed groups and their leaders. Hundreds of residents poured into the streets of Tulkarm late Sunday to protest the attack, witnesses said.

The raid was part of a long day of violence and political protest across Israel and the Palestinian territories.

In Israel, tens of thousands of Israelis linked hands and formed a human chain stretching from the edge of the Gaza Strip to the Old City in Jerusalem to protest Prime Minister Ariel Sharon's intentions to withdraw soldiers and Jewish settlers from the Gaza Strip within the next several years. Police and organizers of the group said the line stretched about 55 miles, though the chain was broken in several places. Organizers said more than 130,000 people participated in the demonstration; police estimated the number at about 70,000 people.

In the southern Gaza Strip, Palestinians fired an antitank rocket into the Jewish settlement of Neve Dekalim on Sunday afternoon, slightly injuring six children when it struck near a community center compound, an Israeli military spokeswoman said. A second rocket or mortar landed on a building in the same settlement later in the day but caused no injuries, she said.

The Israeli air force launched two missile attacks on a house in a crowded Gaza City neighborhood Sunday. Aircraft fired two missiles into the house during the afternoon, and fired more missiles at the same building Sunday night, according to Palestinian security forces. The house was vacant during both strikes, witnesses told the Associated Press.

An Israeli military spokesman said the air force attacked the house because it was being used to manufacture weapons, such as the crude Qassam rockets that Palestinians frequently fire across the Gaza border into Israel. No deaths were reported in either attack.

Israelis formed a chain from the edge of the Gaza Strip to the Old City in Jerusalem to protest Prime Minister Ariel Sharon's plan to pull Jewish settlers and Israeli troops out of Gaza.