Baghdad, Iraq ? Iraqi troops and American soldiers will blockade the roads leading in and out of Baghdad next week in the largest operation ever undertaken by the nation’s new security forces.

The cordon and sweep of the capital – Operation Lightning – comes during an onslaught of car bombs and random violence that has killed more than 600 Iraqis throughout the country since the nation’s interim government took office April 28. U.S. troop casualties also are running at their highest level so far this year.

The operation will include 40,000 police and army troops, and thousands of U.S. soldiers. It could prove to be a watershed event for both the Iraqi security forces and a population in large part still wary of them.

Announcement of the offensive came as Iraq’s interior minister said Thursday that intelligence reports indicated al-Qaida-linked Jordanian terrorist Abu Musab al-Zarqawi, reputedly the mastermind behind bombings that have killed hundreds in Iraq, had been injured.

There have been conflicting statements posted to terrorist Web sites about whether al-Zarqawi was hurt.

The intelligence, “indicates that yes, Zarqawi was wounded. But we do not know the extent of his injuries,” said Bayan Jabr, minister of the interior. Asked how he could be confident of that information, Jabr replied, “It is my job.”

Husam Abdul-Zahra, 17, left, grieves with his friend Haidar Hussein after Husam was wounded and two of his brothers were killed when the minibus they were traveling in was attacked Thursday in southeastern Baghdad.

U.S. officials appeared uncertain of the reports.

“I’d love to be able to confirm or deny that, but the truth is, we are not able to do so,” said Army Brig. Gen. Carter Ham at the Pentagon.

Ham also downplayed the potential impact of al-Zarqawi’s death or capture.

“It’s important to put this in context. While Zarqawi certainly is an important character, his organization is bigger than just one guy,” he said. “It is important, certainly. But if he’s killed or captured, it won’t cause the organization to necessarily crumble.”

Most military officials in Iraq say loyalists to Saddam Hussein’s Baath Party – rather than foreigners associated with al-Zarqawi – make up the backbone of the insurgency.

Insurgent attacks continued Thursday. An Army helicopter crashed after coming under small-arms fire near the town of Baqouba, north of Baghdad, at 10:50 p.m., according to U.S. military officials. Another helicopter also received fire but landed safely. The number of casualties, if any, weren’t known early this morning.