It was one of the bloodiest days in the nearly 17 months of fighting in the Middle East. Officials close to Prime Minister Ariel Sharon said Israel had decided to intensify its military campaign against Yasser Arafat's 8-year-old Palestinian Authority in the days to come.

The Israelis also seemed to be edging closer to a strike against Arafat himself, something they have consistently pledged not to do. A missile that an Israeli helicopter gunship fired at Arafat's headquarters in the West Bank city of Ramallah before dawn today hit within several yards of the Palestinian leader's office.

It is not clear how far away Arafat was at the time, but he emerged defiant. "The tanks and missiles and the planes do not terrify us," said Arafat, 72. "The Israelis insist on avoiding the peace process but we will raise the Palestinian flag on the walls of Jerusalem."

Ten Israelis and at least 27 Palestinians, including two suicide bombers, have been killed in the fighting since Monday.

One new element was that at least seven of the Palestinians killed today were troops in the Palestinian National Security service, which previously has had little involvement in the fighting. The National Security service, which regards itself as the Palestinians' professional army, is by far the largest of Arafat's dozen security forces. If it were to become involved in attacks on Israel the fighting could escalate sharply, according to analysts on both sides.

Defying explicit appeals from the Bush administration, Israel also imposed extraordinarily severe restrictions on Palestinian civilians, closing virtually all major roads in the northern West Bank, where more than 1 million Palestinians live.

The new policy froze Palestinians in their cities, towns and villages shortly before the Muslim feast of al-Adha, a major holiday that most Palestinians spend with their families. The feast is this Friday, so thousands of Palestinians were on the road today trying to reach their home towns, only to be blocked at Israeli checkpoints.

"We don't know how to get home," said Nisreen Abed, 18, one of seven young Palestinian women from a secretarial college in Ramallah who were trying to make their way to the northern West Bank town of Nablus today. "The feast is a special day--mothers make cookies and special meals, they tidy up the house, we all go to see relatives."

But as the women waited near Ramallah, caught in a cloud of dust and exhaust fumes from idling taxis, there seemed to be little prospect of reaching their destination today. Israel halted all Palestinian traffic between major towns in the area, and troops manning roadblocks were under orders to stop others as well.

At the Kalandia Crossing north of Jerusalem, on the seam between Israeli- and Palestinian-controlled territory, reporters watched Israeli soldiers fire warning shots to halt cars driven by a Swiss development worker and European journalists. The Israeli soldiers also blocked Palestinian children who had passed through the checkpoint in the morning from walking home after school.

"I asked him, 'Soldier, let me through.' But he wouldn't let me," said Ghassan Ali, an 8-year-old Palestinian boy who lives just beyond the Israeli checkpoint. He seemed to have no idea how he would get home.

Along with the violence, a new proposal for peace was showing signs today of gathering momentum. Senior Israeli officials are pressing Prime Minister Ariel Sharon to consider a proposal floated by Crown Prince Abdullah of Saudi Arabia.

Under the proposal, Saudi Arabia and other Arab states would establish normal relations with Israel in exchange for an Israeli withdrawal from the West Bank and Gaza Strip, which it occupied in the 1967 war.

The overture comes as Palestinian militants are seeking to focus international attention and Israeli fear on the same beleaguered land.

They have stepped up their attacks in the West Bank, concentrating generally on soldiers and settlers but in particular on Israeli checkpoints. The army said its men guarding such checkpoints here and elsewhere were on high alert.

"This is our new slogan now — break the siege and remove the checkpoints," said Naser Badawi, a senior member of Al Aksa Martyrs Brigades, a militant group linked to Mr. Arafat's Fatah faction.

"It's a hysteria the soldiers are living in," Mr. Badawi said, his Browning 9 millimeter pistol resting on the couch beside him during an interview in the Balata refugee camp near here.

Mr. Badawi noted that, in two days, Israeli soldiers here shot and wounded two pregnant Palestinian women rushing to the hospital along the same tattered stretch of road. "We are losing innocent people" as a result of the new strategy, he said. "But this is the price of occupation."

The Aksa Brigades took responsibility for two attacks today. In one, a gunman opened fire on a bus stop in Neve Yaakov, an area of Jerusalem occupied by Israel in 1967. He wounded eight people, including three policemen, before being subdued by bystanders, apparently when he ran out of ammunition.

In the other attack, gunmen shot at a gray sedan flying a small Israeli flag near the Noqdim settlement. A pregnant Israeli woman riding in the back seat was shot in the stomach.

The woman later gave birth to a girl by Caesarean section at a Jerusalem hospital. She was expected to recover from the shooting.

Two men were killed in the attack, including the woman's father.

Opening fire on a Palestinian car here before dawn, Israeli soldiers wounded a pregnant Palestinian woman and killed her husband as the couple rushed to the hospital up Jerusalem Road.

The husband's father, who was riding beside his son, was in critical condition after soldiers shot him in the chest, hospital officials said.

After the shooting subsided this morning, "I started shouting, `Baby, baby,' " said Maysoun al-Hayek, 22, as she lay in the hospital sobbing and cradling her newborn daughter, Fidah, or Sacrifice. She said soldiers at a checkpoint at the entrance to Nablus had thoroughly inspected the car.

A spokesman for the Israeli Army, Jacob Dallal, said that the Hayeks' car had burst through a temporary roadblock and that the driver had ignored shouts to stop.

Mrs. Hayek said that when she was lying on the ground after the shooting, soldiers forced her to disrobe to prove she was not a threat. Mr. Dallal disputed that account.

Mrs. Hayek gave birth immediately after arriving at the hospital. She said when she first felt the stirring of labor, her husband asked her to try to hold out until 5 a.m., reminding her of the shooting on Sunday morning. But by 1:30 a.m., she said, she could not wait any longer, and they set off from their village for the hospital.

"Before leaving, my husband said, `I'm not sure if I'll see this baby or not,' " she said.

The Israeli Army has seized positions overlooking the densely packed Balata camp. People in the camp have used burned husks of cars and Dumpsters piled with trash at its entrances to block the soldiers. Jerusalem Road is strewn with appliances, rocks, Dumpsters, and the coils of wire left from burned tires.

Several residents said they had been turned out of their homes by Israeli soldiers, while others contended that they were being kept inside for use as human shields. Mahmoud Hindieh said he and 29 other Palestinians were herded into one apartment in a building held by soldiers.

The Israeli Army denied that account, saying everyone was free to leave the building if they chose.

Esam Shehadah, 31, arrived at the hospital here this afternoon to pick up his wife, Shadiya, who was shot through the shoulder on Sunday while they drove to the delivery room. "We were lucky," he said with a relieved smile.

The Shehadahs also passed the checkpoint after a search, before being fired upon. The army said it had moved a roadblock, but Mr. Shehadah said no one told him to stop and he saw no signs of a roadblock. "It's like a trap," he said. "The checkpoint lets you inside, and then they shoot."

Mr. Shehadah, who speaks Hebrew and English as well as Arabic, said that after he convinced the soldiers that his wife was pregnant and wounded, he had a glimpse of humanity in the chaos. "There was one person, I thought he was a human being — the doctor," Mr. Shehadah said, describing a soldier with medical training who came to his aid. "He didn't apologize, but he patted my shoulder and said:`She's O.K., she'll be O.K. Don't worry.' "