The Pentagon is investigating whether a recent attack on a military compound in Karbala was carried out by Iranians or Iranian-trained operatives, two officials from separate U.S. government agencies said.

"People are looking at it seriously," one of the officials said.

That official added the Iranian connection was a leading theory in the investigation into the January 20 attack that killed five soldiers.

The second official said: "We believe it's possible the executors of the attack were Iranian or Iranian-trained."

Five U.S. soldiers were abducted and killed in the sophisticated attack by men wearing U.S.-style uniforms, according to U.S. military reports. (Watch how attackers got into the compound Video)

Both officials stressed the Iranian-involvement theory is a preliminary view, and there is no final conclusion. They agreed this possibility is being looked at because of the sophistication of the attack and the level of coordination.

"This was beyond what we have seen militias or foreign fighters do," the second official said.

The investigation has led some officials to conclude the attack was an "inside job" — that people inside the compound helped the attackers enter unstopped.

Investigators say they believe that attackers who used American-style uniforms and weapons to infiltrate a secure compound and kill five American soldiers in Karbala on Jan. 20 may have been trained and financed by Iranian agents, according to American and Iraqi officials knowledgeable about the inquiry.

The officials said the sophistication of the attack astonished investigators, who doubt that Iraqis could have carried it out on their own — one reason a connection to Iran is being closely examined. Officials cautioned that no firm conclusions had been drawn and did not reveal any direct evidence of a connection.

A senior Iraqi official said the attackers had carried forged American identity cards and American-style M-4 rifles and had thrown stun grenades of a kind used only by American forces here.

Let’s assume the attackers fooled the Iraqi guards with their broken English, uniforms and vehicles, but what about their weapons? Were they carrying AK-47’s or M-4’s and M-16’s? Someone in the checkpoints must have seen some of the weapons and at least got a little bit suspicious seeing no American weapons in the vehicles.

Even stranger, no one chased the attackers after that and the excuse is even harder to accept:

When asked why Iraqi police did not intervene to stop the gunmen from fleeing, al-Mishawi said “they assumed it was American-on-American violence and wanted to stay out of it.”

As if this “American-on-American” violence were a daily occurrence!

No Iraqi soldiers, policemen or officials were hurt in the attack. The attackers knew about the timing and location of the meeting and they were certainly not al-Qaeda fighters or Sunni insurgents. I mean why would al-Qaeda or Sunni insurgents risk making the very dangerous trip to the heart of Kerbala to kill American soldiers while they could’ve inflicted more casualties by planting a few IED’s in the streets of places they control? Plus, they wouldn’t have spared the lives of the Iraqis in the building.

If I remember well, some time ago the head of the provincial council was arrested under charges of terrorism, so the local authority in Kerbala isn’t exactly trustworthy.
The governor said there was a security breach but what I smell here is the stench of an inside job at the highest levels in Kerbala.

Like I said earlier, this was not just a brazen attack by some militia or terrorists; behind this is a message and a threat from Iran and its surrogates to turn even the calm parts of Iraq into a dangerous war zone for America and the government in Baghdad.