The bomber boarded crowded bus No. 960 during morning rush hour Wednesday, at its first stop en route to Jerusalem. A few minutes later, he set off a blast that lifted the bus a few feet into the air, peeled back the roof and hurled some passengers onto the highway. 

At least nine people died, including the bomber, and 14 were injured, police said. It was the fourth suicide bombing since Israel began its massive military offensive, "Defensive Shield," on March 29 to wipe out Palestinian militants. 

"There was a huge bang. I saw the man exploding near the front," said Gal Marom, a 20-year-old soldier being treated at a Haifa hospital for cuts on his chest. "I went flying and landed on the steps of the back door. I staggered out and managed to walk a couple of steps. I even phoned my father so that he wouldn't worry — he knew I was on the bus." 

Rami Solomon described the scene, near his office. 

"There were body parts scattered on the road with legs blown off, shoes and army boots lying around, ambulances with sirens wailing," Solomon said. 

The Islamic Hamas militant group claimed responsibility for the attack in an announcement on its Web site. 

"To [Israeli Prime Minister Ariel] Sharon and his ministers and generals, we have shown that there is no 'Defensive Shield,"' the site said. 

Sources in Hamas identified the bomber as Ayman Abu Haija, 22, from the Jenin refugee camp in the West Bank. It was unclear when he left the camp, which has been under Israeli siege for a week. 

Ismail Abu Shanab, a Hamas leader in the Gaza Strip, said the bombing was a "clear message that our people will not surrender and will not give up." 

Yaakov Borovsky, a police chief in northern Israel, said the suicide bomber wore an explosives belt and detonated it shortly after boarding the bus. The explosion went off near Kibbutz Yagur, a communal farm just east of Haifa, near the Carmel mountain range, and about 15 miles from the West Bank. 

One witness, identified only by his first name, Motti, told Israel Radio he was driving about 60 feet behind the bus when he heard the explosion and saw the bus fly 6 to 10 feet into the air. 

"Shrapnel and bits are everywhere," Motti said. 

Rescue workers arriving moments later covered several bodies lying on the asphalt with white sheets and blankets. Personal belongings were strewn on the highway, including an olive jacket of the type worn by soldiers, a backpack, a skullcap and identity papers. 

The 7:15 a.m. blast punched a large hole through the roof of the front of the bus, blew off the wheels and shattered the windows. The bus was resting on its side where it came to a rest — on the divider of the six-lane highway. 

Israeli authorities shouted "Get back! Get back!" through a megaphone, trying to keep journalists and the rapidly growing crowd of onlookers behind orange tape. Religious volunteers cleaned up the blood and body fragments on the highway, while authorities with yellow protective booties over their shoes inspected the bus. 

A few hours after the blast, the bus frame was hauled away and a street-cleaning vehicle was vacuuming away the remaining traces of the blast. 

Wednesday's suicide bombing was the fourth since Israel launched its military offensive aimed at crushing Palestinian militias that have carried out numerous such attacks on Israeli civilians in the past 18 months. The first, also in Haifa, went off March 31 when a suicide bomber blew himself up in a crowded restaurant, killing 15 people. 

Arieh Mekel, an Israeli government spokesman, said the bombing was a sign that the Palestinians were intent on disrupting a new peace mission by Secretary of State Colin Powell, who is to arrive in the region Thursday. 

Israeli Health Minister Nissim Dahan angrily criticized U.S. demands to immediately end the military operation. 

"If there are more victims like these, the United States government, President Bush and also Colin Powell — who want us to stop the operation — will be held responsible," he said during a visit at Haifa hospital. 

Palestinian Information Minister Yasser Abed Rabbo said he was more concerned about violence in the Jenin refugee camp, scene of the deadliest fighting during the military offensive.