The opening salvo against Saddam was not the expected all-out aerial bombardment, but instead a surgical strike seeking to eliminate the Iraqi leader and his inner circle even before an invasion. Saddam, in a TV appearance, assailed the attack as a "shameful crime," while President Bush said the world's security was at stake. 

Iraqi Information Minister Mohammed Saeed al-Sahaf said the U.S. strikes killed one person, injured several and hit a customs office and some empty Iraqi TV buildings, among other targets. There was no way to verify his report. 

Coinciding with the strikes on Baghdad, about 1,000 U.S. troops launched a raid on villages in southeastern Afghanistan, hunting for members of the al-Qaida terrorist network. The U.S. operation - triggered by radio transmissions intercepted from caves in the region - appeared to signal to Osama bin Laden and his lieutenants that war with Iraq would not mean any respite for them. 

The State Department warned U.S. citizens abroad that they face increased danger of retaliatory terrorist actions and anti-American violence. The U.S. Embassy in Pakistan was shut down because of security concerns. 

The first missiles hit targets in Baghdad shortly before dawn Thursday, less than two hours after Bush's deadline of 8 p.m. EST Wednesday for Saddam to yield power. 

Bush briefly addressed the nation to announce that the war had begun. He said the barrage marked the start of a "broad and concerted" operation to "disarm Iraq, to free its people and to defend the world from grave danger." 

"I assure you, this will not be a campaign of half measures, and we will accept no outcome but victory," the president said. 

U.S. and British troops massed in northern Kuwait were still awaiting orders to cross into Iraq, but welcomed news of the first strikes. 

"It's about time," said Lance Cpl. Chad Borgmann, 23, of Sidney, Neb., a member of the 15th Marine Expeditionary Unit. "We've been here a month and a week. We're ready to go." 

Even before any shooting, 17 Iraqi soldiers surrendered to American soldiers. U.S. officers said they expected mass surrenders by Iraqi troops in the early stages of the war that the United States calls Operation Iraqi Freedom. 

The initial salvos against Baghdad consisted of 40 Tomahawk cruise missiles launched from Navy ships in the Persian Gulf and the Red Sea, as well as precision-guided 2,000-pound bombs dropped from two F-117A Nighthawk stealth jets. 

U.S. officials said the attacks were not a sign that the main air offensive against Iraq had begun, but were approved by Bush in response to intelligence that Saddam and his sons, Qusai and Odai, might be sleeping in one of the targets. Officials said it was unclear whether any of them were actually near the target. 

About two hours after the cruise missiles hit, a subdued-looking Saddam appeared on Iraqi television in a military uniform. There was no way to determine immediately whether the remarks were taped before the U.S. attacks. 

"We promise you that Iraq, its leadership and its people will stand up to the evil invaders," he said. "They will face a bitter defeat, God willing." 

Hundreds of armed members of Saddam's Baath party and security forces took up positions in Baghdad after the attack, though streets were mostly empty of civilians. There were no signs during the day of regular army troops or armor in or outside Baghdad. 

Across the United States, the start of war was an emotional moment for families of U.S. troops. 

"I thought I was prepared for this, but I'm really not," said Suzanne Hoefler of Coronado, Calif., whose husband, Navy Petty Officer John Hoefler, left in January for the Persian Gulf. 

State and local authorities intensified security measures, hoping to shield power plants, bridges and other facilities against possible retaliatory strikes. In New York City, police prowled streets with bomb-sniffing dogs, submachine guns and radiation detectors. 

"There is a two-front war here," Mayor Michael Bloomberg said. "One is on the streets of our cities, and one is overseas." 

In other nations, reactions varied dramatically. Both Russia and China demanded an immediate halt to the military action, which Russian President Vladimir Putin called "a big political mistake." Religious parties in Pakistan called for a general strike to protest U.S. policy, and hundreds of stone-throwing anti-war protesters in Egypt clashed with riot police. 

Support for Washington came from allies Britain and Japan, among others. Australia, which has contributed 2,000 soldiers to the U.S.-led force, said its warships and fighter jets were involved in combat support operations Thursday. 

In Israel, civilians began carrying gas masks and air defense units were placed on highest alert to intercept any incoming Iraqi missiles.