BAGHDAD (AP) - The U.S. military said Friday that bullets fired by American soldiers killed the 14-year-old son of the chief editor of a U.S.-sponsored newspaper during a gunbattle this week in the northern Iraqi city of Kirkuk.

The military said Arkan Ali Taha was hit when soldiers came under heavy gunfire from a passing taxi and shot back. The boy was riding in the cab and the driver was later taken into custody, the statement said.

The father said his son was not involved with extremist groups and didn't know how to use weapons. He said the boy had hired the cab to bring a set of keys to the newspaper.

American and Iraqi security forces have been cracking down on insurgents in the northern cities of Kirkuk and Mosul and in the restive Diyala province north of Baghdad, where violence has been slower to decline than elsewhere in Iraq.

According to the U.S. statement, American troops were trying to recover a disabled vehicle in Kirkuk on Wednesday when multiple shots were fired at them from the taxi. One soldier was wounded, it said.

"The soldiers returned fire, killing a young Iraqi man in the taxi," the military said, adding that Iraqi police later detained the driver.

The boy's father, Ali Taha, who is chief editor of the U.S.-sponsored Voices of Villages newspaper, said he had asked his son to bring the keys to his office.

He insisted his son was not armed and said he didn't believe the taxi driver was either.

"My son was only 14 years old," he told The Associated Press. "He is neither a terrorist, nor a gun carrier. He didn't even know how to use a pistol. The only thing he knew how to use was the computer."

Tensions have been rising in Kirkuk as minority Kurds step up efforts to incorporate the diverse city into their semiautonomous territory in northern Iraq despite objections from Arab and Turkomen factions.

In violence Friday, a bomb left in a plastic bag exploded on a minibus in the Shiite holy city of Karbala, wounding nine people, including a woman, police said, raising security concerns as authorities prepare for a Shiite pilgrimage next month.

The attack occurred about 500 yards from the golden domed mosque of Imam Abbas, the half brother of one of Shiite Islam's most revered saints, Imam Hussein, who is buried in a nearby shrine.

Pilgrims are expected to begin pouring into Karbala next week for a festival marking the birth of Mohammed al-Mahdi, the 12th and last Shiite imam who is known as the Hidden Imam because he disappeared in the 9th century. Devout Shiites believe he will return to Earth to usher in the rule of peace.

Security forces in Karbala, 50 miles south of Baghdad, have been instructed to prevent pilgrims from carrying sectarian posters or banners, the city's police chief, Brig. Gen. Raed Shakir Jawdat, said Friday.

Also banned will be cell phones, sticks and white shrouds that are frequently worn by followers of anti-U.S. cleric Muqtada al-Sadr, Jawdat said.

He said some 40,000 Iraqi security officers - including snipers, riot police and rapid response forces - will be deployed for the festival, which will culminate in mid-August. Some 2,000 armored vehicles and 10 helicopters also will be deployed, he said.

At least two explosions were heard in Baghdad Friday evening. Iraqi police said they were controlled blasts to destroy ammunition dumps at U.S.-Iraqi bases in western and eastern Baghdad and no casualties were reported. The U.S. military said it had no immediate information about the blasts.

Associated Press writer Mazin Yahya contributed to this report.

(This version CORRECTS Corrects that shooting was Wednesday, not Thursday.)