Pressing his foot to the gas pedal as he closed on the white Mercedes-Benz in front of him, the bomber sped toward his target: a senior Iraqi official.

A burst of white light followed, and a boom, muffled by the concrete blast walls that ring Baghdad's Green Zone. Shreds of bloody cloth and flecks of flesh rained upon stunned survivors. Among them, witnesses said, was the targeted Interior Ministry official, standing in the gore and flame, unscathed.

The unknown attacker ended his life on the first day of the holy month of Ramadan, when some radical Muslims believe the gates of Heaven open and those who die in the name of the faith have their entrance to Paradise guaranteed. Two fist-size gobbets of soot-streaked flesh dangled from coiled concertina wire.

It was the opening of a month in which ever-more-weary and ever-less-hopeful Iraqis fear that violence here -- already risen to a level of carnage few imagined when U.S. troops entered 21/2 years ago -- will only get worse.

Ramadan is normally one of the happiest periods of the Islamic calendar, one when aunts, uncles and cousins assemble after day-long fasts for elaborate meals. Children stay up into the early hours for TV and conversation. Men head out to cafes for smoky late-night outings.

In more peaceful times, commercial districts in Baghdad would be thick with people at the close of each day, as shoppers gathered food for the nighttime gatherings. But Ayad Abu Jihad, a salesman standing unhappily in his empty appliance store in the Karrada neighborhood, said: "This is nothing like Ramadan."

On Tuesday, Karrada's streets were barren of crowds. Almost all of those out late in the day were men. Most women, fearful of kidnapping and bombings, yielded shopping and other errands.

Shopkeepers and shoppers said nothing of happiness this Ramadan.

"There aren't many customers, and it's all because of bad security," said Abu Jihad, 35, idle in his darkening shop. "What's more, the situation will deteriorate more with the coming referendum. I expect more violence and more explosions."

Ramadan last year had a surge of violence -- although the dozen deaths recorded on the worst day of that season have become standard daily fare in Iraq, ever since insurgents stepped up attacks with the seating of Iraq's U.S.-backed transitional government in late April.

This Ramadan coincides with Iraq's Oct. 15 national vote on a proposed constitution. U.S. officials from President Bush on down have warned that insurgents will likely increase attacks to taint the milestone in Iraqi efforts at government-building. Factional tensions -- among Shiites, Kurds and Sunnis -- also have increased over the document.

The Western calendar has been just as grim. September was the bloodiest month yet in Iraq in terms of multiple-fatality insurgent bombings, according to figures kept by the U.S.-based Brookings Institution. Such bombings killed at least 481 people and wounded 1,074, Brookings reported.

September also had by far the most multiple-fatality bombings: 46 that killed three or more people, according to Brookings.

"No! No! No!" a young Iraqi man screamed after Tuesday's bombing as he crouched behind the sandbags and barricades of one of the outer checkpoints at the Green Zone, the base of the U.S. presence in Iraq and the new Iraqi government.

The blast had blown part of the man's right hand from his wrist. He held his right hand on with his left, bone sticking out and strings of clotting blood falling to the checkpoint concrete.

A U.S. soldier ripped the man's shirt from his back, kneeling down to gnaw it with his teeth, tearing it to make a bandage. The Iraqi screamed as the American inadvertently tugged him this way and that.

Iraqi and U.S. soldiers outside the first checkpoint dealt with the burning cars and other aftermath of the blast, as the nervous gunfire that follows most bombings here played out. Soldiers from the former Soviet republic of Georgia, who help man Green Zone checkpoints, crouched behind sand barriers inside.

A private guard from Nepal, hired by a Western firm that also provides security in the Green Zone, poured water on the stains left behind by the Iraqi man. He rubbed clods of dirt into the blood with his foot.

The target of Tuesday's bombing was a senior official in the Interior Ministry, said Army Lt. Col. Bob Roth, commander of the 1st Battalion, 64th Armor of the 3rd Infantry Division, whose region includes the Green Zone. The Americans withheld the identity of the official, because, they said, he had been targeted previously.

The bomber had been following the official, unnoticed by the man's security detail, Roth said. The site of the attack had only coincidentally been the Green Zone, officials said.

Hitting the gas as the cars passed the zone, the attacker steered between the official's white Mercedes and a security car and blew himself up, Roth said.

U.S. military officials said they knew of only one death, that of the bomber, and a few injuries among Iraqi soldiers -- not a high toll for Baghdad, given the apparent size of the bomb, a military official noted. Iraqi police, however, told news agencies that two police officers had been killed, and witnesses said they saw two bodies being carried away in the back of a police pickup truck.

It was the first bombing of Ramadan, for Baghdad.

"Nothing will change the course of events,'' Jamal Ali, 31, an electrical technician who works for Abu Jihad, said after walking into the appliance store.

The optimism that many Iraqis had managed to sustain -- despite bombings -- after the elation of January's national elections seems gone less than two weeks before the next round of voting.

"Things are heading for the worse, and I expect more deterioration, more violence, because the course of events is set in that direction," Abu Jihad said. He spoke of neighborhoods he no longer visits because of violence, of barely escaping a kidnapping attempt in one.

"A real change has taken place inside people's minds and hearts, and it is going to take a long time to reverse the course,'' he said, on the unhappy, quiet street. "People are being killed because they are Shiites, and others are killed because they are Sunnis. This is terrible."

Iraqi forces secure Baghdad's Green Zone after yesterday's suicide bombing.