BAGHDAD - A car bomb exploded in the city's busiest intersection yesterday, killing at least eight people and injuring 64, underscoring the violence still facing Iraq despite a drop in attacks in recent month.

Like a similar explosion last month at a popular pet market, the blast at central Baghdad's crowded Tahrir Square came on a day when many Iraqis are running errands and patronizing local vendors.

A 6-year-old boy and two teenagers were among those killed in the latest explosion, not far from one of the main, heavily guarded entrances to the Green Zone, police said. Officials provided conflicting numbers, with some putting the death toll as high as 14.

Witnesses told police that street vendors noticed a man in his late 20s parking his car near their booths, but they asked him to leave for security reasons, according to the preliminary investigation.

He promised he would not be more than five minutes, bought some items, loaded them into his car, then disappeared into the crowd before the car exploded, damaging several vehicles as well as fruit and vegetable stalls, police said.

"I saw this great blaze, and when the initial shock subsided, I ran toward the area," said Haydar Muhsin, 37, a minibus driver who estimated he was a little more than 100 yards away.

"I immediately saw two charred corpses in addition to others who were slashed by shrapnel."

Muhsin said it was not until later that he realized he had suffered wounds on his upper arm and neck. He was taken to the hospital in an ambulance but did not sustain any serious injuries.

In recent weeks, buoyed by the lull, the municipality had put special effort into rehabilitating the square, its gardens and a monument.

A spokesman for the city said it had become commonplace to fix up areas, only to see them damaged or destroyed a few days later.

"When I watch TV, I do get angry," Hakeem Abed Zahra said. "We will beat them. We lost 1,000 of our workers on duty in Iraqi streets, but although human lives are irreplaceable, we will continue our loyal commitment and send our workers back to Tahrir Square to fix what these terrorists have destroyed."

Elsewhere, the U.S. military said five suspected insurgents were killed and 14 detained in an operation in central and northern Iraq.

Four of the suspects were killed in an operation north of Muqdadiya, 60 miles northeast of Baghdad. A fifth suspect, an alleged cell leader for al-Qaeda in Iraq, was killed near Salman Pak, southeast of Baghdad.

Petraeus: Focus Must Shift in Iraq

The U.S. military

in Iraq must shift its focus toward helping the government restore basic services

and boost the economy, while still holding on to fragile security improvements, said the top U.S. general in Iraq.

In a letter

to his troops, Gen. David Petraeus said that even as the United States begins to pull out forces from Iraq, the military must capitalize on

the recent decline in attacks and casualties.

"While the progress

in a number of areas is fragile, the security improvements have significantly changed the situation in many parts of Iraq," Petraeus said in the letter sent yesterday. "It is

now imperative that we take advantage of these improvements by looking beyond the security arena and helping Iraqi military and political leaders as they develop solutions in other areas

as well, solutions they can sustain over time."

Specifically, he said

, troops need to help the Iraqi government create jobs, revitalize markets, refurbish schools, and restore critical services.

- Associated Press