Associated Press Four-year-old Palestinian boy Hussein Jarboo holds an AK-47 assault rifle during an anti-Israel and anti-U.S. rally organized by the Palestinian Public Resistance in Rafah, southern Gaza Strip, yesterday. The headband says, "Friends of Martyrs."

JERUSALEM - A Palestinian gunman opened fire at a bus stop in north Jerusalem late yesterday, capping a day of violence in which four people were killed and two pregnant women - one Israeli and one Palestinian - were shot at roadblocks and then gave birth to healthy babies.

The gunfire threatened to rekindle daily Israeli-Palestinian bloodshed after a brief period of relative calm. A senior Israeli official said that understandings reached last week toward calming the violence were no longer in effect because of Palestinian attacks, and that Israel would respond.

The bus stop attack took place after nightfall in Neve Yaakov, a Jewish neighborhood in a disputed part of Jerusalem claimed by both sides. At least one Palestinian started shooting at Israelis, wounding eight people, including three policemen, police and witnesses said.

Eyewitness Yulia Kizgila, 23, saw the gunman. "He ducked behind a car and fired," and police fired back, she said. The car was riddled with bullets and the street was smeared with blood.

Police charged the attacker and shot him, said Jerusalem police commander Mickey Levy. At first, police said there were two gunmen and one was killed. Later, they said one was critically wounded, and two hours after the incident they said there was only one attacker.

In Nablus, the Al Aqsa Brigades said the attacker belonged to the group, linked to Palestinian leader Yasser Arafat's Fatah movement. The organization also claimed responsibility for another attack on Israelis yesterday.

Earlier in the day, Israel pulled back the tanks surrounding Arafat's compound in the West Bank. Angry Palestinian officials said the move was meaningless because of the continued restrictions on the movements of the Palestinian leader.

The day's violence began in the West Bank, where two Palestinians were shot and killed by Israeli troops in separate confrontations at military checkpoints. Shortly before the bus stop attack, two Israelis died in a gunfire attack at a roadblock near the isolated Jewish settlement of Nokdim, south of Bethlehem.

One of the Palestinians killed was taking his pregnant wife to the hospital in Nablus. The woman, who was slightly injured, gave birth to a girl shortly after her husband died. It was the second day in a row a pregnant Palestinian woman heading to the hospital was wounded by Israeli gunfire at the same checkpoint in Nablus.

In both shootings of pregnant Palestinians, the Israeli military said soldiers opened fire after the cars ignored orders to stop and tried to drive around the roadblock. Israeli soldiers at checkpoints have been especially wary since six soldiers were killed by Palestinian gunmen in a roadblock attack last week outside the West Bank city of Ramallah.

In the nighttime attack on Israelis in which two men were killed, a pregnant Jewish woman was seriously wounded and gave birth to a healthy baby. One other person was injured in the shooting, for which the Al Aqsa Brigades claimed responsibility in a telephone call to The Associated Press. In another attack near Hebron, a 16-year-old Israeli boy was seriously wounded, the military and Jewish settlers said.

Also yesterday, a Palestinian girl was killed when she ran toward an army checkpoint near Tulkarem brandishing a knife, the army said. Soldiers shot her after calling on her to stop and firing warning shots in the air, the army said.

The girl's father, Jamal Shalhoub, said his 16-year-old daughter, Noura, had been deeply affected by the violence and that apparently moved her to attempt an attack on Israeli soldiers.

In another checkpoint incident, Israeli soldiers near Ramallah opened fire Sunday night on a car belonging to a senior Palestinian official, Ahmed Qureia. His car was hit by bullets, but no one was hurt.

Israel, which has kept Arafat confined to Ramallah for nearly three months, withdrew tanks early yesterday that had been about 100 yards outside his government compound.

However, Israeli troops will remain posted around the city's perimeter, the army said, and Arafat will not be allowed to leave the city, the Israeli government said.

The Palestinians had hoped last week's arrests of three top suspects in the October killing of Israeli Cabinet minister Rehavam Zeevi might end Arafat's confinement. But on Sunday Israel demanded again that they be handed over to Israel and that other suspects be arrested as well.

Israel will hit back for the latest Palestinian attacks, said Raanan Gissin, Prime Minister Ariel Sharon's spokesman. He said understandings reached Thursday in a meeting of security commanders are off. Israel removed some roadblocks and withdrew from some positions in Gaza, and the Palestinians pledged to work for an end to the attacks.

Now, Gissin said, "it is clear that the other side planned to renew the violence." He said Israel would retaliate in what he called a "measured response." In the week before the security meeting, Israel pounded Palestinian security buildings and checkpoints and killed almost 50 Palestinians, responding to bloody Palestinian attacks.

In yesterday's shooting of the pregnant Palestinian woman, Mohammed Hayek was driving his wife Maysoun from their West Bank village to the Rafidia hospital in Nablus after she went into labor.

As they approached a checkpoint, Mohammed Hayek was hit in the neck by a gunshot, his wife said afterward at the Rafidia Hospital.

According to the army, soldiers opened fire when a car tried to get past an earthen barricade blocking the road and ignored soldiers' orders to stop. When the driver attempted to reverse in order to detour around the temporary roadblock, soldiers shot at the car, the army said.

After the car came to a stop, Hayek opened the door and began yelling "baby" in English, she said. Soldiers approached and began administering first aid, placing her and her critically wounded father-in-law on stretchers, she said.