BAGHDAD, Iraq - A bomb hidden in a box of pigeons exploded Friday as shoppers gathered around, tearing through a busy pet and livestock market and littering the blood-soaked pavement with human remains and animal carcasses.

At least 62 people were killed or found dead nationwide, including a U.S. Marine.

The attack at the popular weekly animal market shattered the calm as Baghdad residents strolled past stalls where sellers were peddling birds, dogs, cats, sheep, goats and exotic animals such as snakes and monkeys.

"I went this morning to the animal market to earn some money and to entertain myself. Instead I was hit by the explosion and lost ... my pigeons and my mobile phone," Sajad Abdel-Jabar, an 18-year-old homing pigeon vendor, said from his hospital bed.

No one claimed responsibility for the bombing, which police and hospital officials said killed 15 people and wounded 66. Suspicion fell on Sunni insurgents because the market sits near a predominantly Shiite neighborhood on the east bank of the Tigris River that divides Baghdad.

It was the latest in a series of attacks on busy commercial targets in the capital as insurgents apparently sought to maximize bloodshed ahead of a U.S.-Iraqi security crackdown.

Attacks elsewhere left at least 46 people dead, including 38 bullet-riddled bodies found mostly in Baghdad. The body of a Shiite boxer who had been kidnapped days ago also was found in central Baghdad, with wounds on his neck indicating he had been hanged, police said.

A Marine was killed in fighting in the Sunni insurgent stronghold of Anbar province, west of Baghdad, the military said, raising the number of U.S. service members who have died since the war began to at least 3,070, according to an Associated Press count.

U.S. House Speaker Nancy Pelosi (news, bio, voting record) and Rep. John Murtha (news, bio, voting record), both vocal war critics, met with Iraqi Prime Minister Nouri al-Maliki in the Green Zone a day after a rocket attack on the heavily fortified complex wounded six people.

"We come out of the meeting with a greater understanding of the others' point of view," Pelosi said, adding that the delegation also made the visit "to convey to our troops the appreciation of the American people for what they're doing, to applaud their patriotism."

Pelosi has been a sharp critic of the Bush administration's conduct of the war and has led a drive in Congress against sending in 21,500 more troops as part of a new security crackdown.

In Washington, President Bush challenged skeptical lawmakers Friday not to prematurely condemn his buildup, saying "I'm the decision-maker."

The explosion struck the Souq al-Ghazl at about 10 a.m., one of the busiest times for the animal vendors and an hour before the start of a four-hour vehicle ban that is imposed every Friday to prevent car bombs from striking mosques during weekly Islamic prayers.

The bomb detonated in the part of the market that specializes in birds; other areas are reserved for fish, dogs or other animals.

The suspected bomber arrived with an egg carton containing pigeons for sale, but it exploded after he walked away to get a drink, striking potential buyers gathered around the box, according to police and witnesses.

Raad Hassan, a frequent customer at the market, said he was about 60 yards away from the blast.

"My friends and I rushed to the scene where we saw burned dead bodies, pieces of flesh and several dead expensive puppies and birds," he said.

Ali Nassir said dead animals were scattered on the bloody ground and several snakes, monkeys and birds had been let loose from their cages as ambulances and police cars converged on the scene.

"The policemen are firing in the air in order to disperse the crowds of people arriving to find out what happened to relatives who were missing," he said. "The explosion was huge."

The al-Ghazl market, or Spinning Market, also was attacked in June, when two bombings struck in quick succession, killing at least five people.

The popular market stands next to the 13th century Sunni Ulama Mosque built by the Abbasid dynasty. The shops around the mosque used to be known for their spinning mills but the area evolved into an animal market a few decades ago.

The shops are open all week but vendors come on Fridays and set up stalls on the 1,500-foot-long stretch of pavement on Jumhuri Street.

Anger also mounted in the central commercial district of Karradah a day after a suicide car bomber struck the mainly Shiite area, killing at least 30 people, including a local tea vendor and several people in a cafe, according to residents. Many Shiites in the neighborhood have called for revenge against Sunnis.

Police found a bomb in the same area apparently targeting a Shiite procession that was part of the 10-day Ashoura festival, which marks the death of Imam Hussein, grandson of the Prophet Muhammad. The bomb could not be defused so police detonated the explosive device in a controlled blast, which damaged several stores.