BAGHDAD, Iraq — The American military said yesterday that the arrest of Al Qaeda in Iraq’s second in command took place in June and was the most significant blow to the terror network since the death of Al Qaeda in Iraq leader Abu Musab al-Zarqawi.

Violence continued around the country, with at least 28 people dying in shootings and bombings that also wounded at least 53.

Major General William Caldwell said Hamed Jumaa Farid al-Saeedi, also known as Abu Humam or Abu Rana, was captured on June 19 — not a few days ago as the Iraqi government had initially announced.

“As with most terrorists that are picked up, they are not initially announced as being captured because of the intelligence value that is normally gained from somebody not knowing that they are in fact in Iraqi government control,” General Caldwell said. “There are other people in captivity right now who are not announced.”

Iraq’s national security adviser, Mouwafak al-Rubaie, announced Mr. Saeedi’s arrest on Sunday, saying it had occurred a few days earlier. But General Caldwell said it was only the permission to announce the arrest that had been given a few days earlier.

Mr. Caldwell called the arrest the most significant since Zarqawi was killed in an American airstrike on June 7.

Mr. Saeedi “provided an enormous amount of intelligence,” he said.

“There is no question that the Al Qaeda in Iraq network has been degraded and disorganized here in Iraq,” he said during a separate interview with Associated Press Radio.

But he warned that the organization is resilient. “They’re still going to be able to do strikes at different times that gain sensationalism on TV,” he said.

He added that the man who masterminded the February 22 bombing of a Shiite shrine in Samarra reported directly to Mr. Saeedi. That attack, 60 miles north of Baghdad, inflamed tensions between Shiite and Sunni Muslims and triggered months of reprisal attacks that have killed hundreds of Iraqis.

The spokesman said a link existed between the intelligence gathered during the operation that killed Zarqawi on June 7 — and other operations that directly followed his death — and Mr. Saeedi’s capture less than two weeks later. General Caldwell would not say what the link was.

Also yesterday, two bombs exploded in northern Baghdad within minutes of each other, killing at least nine people and wounding 39 others, police said.

The blasts — from a parked car bomb and a roadside bomb — had targeted a passing Iraqi army patrol at a busy intersection during the morning rush hour as people headed to work, police First Lieutenant Mohammed Khayun said.

The car bomb was parked in front of a tire repair shop, a witness, Abdel-Majeed Salah, told AP Television News. He said a minibus with passengers on board was behind the parked car when it detonated, and all on board were killed.

Two of the dead and eight of the wounded were Iraqi soldiers, police said.

In northeastern Baghdad, gunmen opened fire on a procession of pilgrims heading to the Shiite holy city of Karbala, 50 miles south of Baghdad, killing one person and wounding two, police First Lieutenant Ali Abbas said.

Tens of thousands of people are expected in Karbala, 50 miles south of the capital, on Saturday to observe Shaaban, a religious celebration. Many of the pilgrims travel to the city on foot.