Baghdad's airport is under heightened security and Iraqi pilots are being investigated after an alleged Al Qaeda plot to hijack a plane and fly it into one of Iraq's shrines in a 9/11-style attack, Iraq's foreign minister said Thursday.

"They were either going to hijack some planes abroad - we had tips from Czech (authorities) and from Interpol that suspicious Iraqis were trying to intercept a plane... and (strike) some very emotive sacred targets," Foreign Minister Hoshyar Zebari told The Christian Science Monitor. He said the potential targets included shrines in Najaf and Karbala - two of Shiite Islam's holiest sites which receive thousands of foreign pilgrims a week. He said the alleged attackers were planning to execute the plan in about 45 to 60 days.

A senior US military official speaking on condition of anonymity said their intelligence indicated that the planes were intended to be hijacked in Baghdad. He said two Iraqi Airways pilots had been detained for questioning in connection with the alleged plot.

There have been other failed attempts to replicate the 9/11 attacks. In 2007, Saudi Arabia said it disrupted an Al Qaeda plot to fly planes into oil refineries in the kingdom.

The Najaf airport has been shut down for almost a week and is expected to reopen by Sunday. Airspace around the city was also placed off limits to civilian aircraft. The Baghdad airport was closed for several hours last week and later reopened but remains under heightened security, Mr. Zebari said. Iraqi officials originally said the closures were needed to repair a problem with radar but later acknowledged it was a security operation.

Background checks

Zebari said Iraqi authorities have run checks on all Iraqi pilots but has not found evidence that any commercial pilots were involved.

"I think the danger may still be there but the government is trying to take every conceivable precaution," he said, adding that ministries continued to function normally despite political wrangling over forming a new government following elections early last month.

US officials say there appears to have been a plot but that it was believed to be in the early planning stages. Zebari said alternate plans involved storming the Baghdad airport under the guise of a security convoy or using small crop dusters packed with explosives to crash into either the parliament building, embassies, or other government targets.

Al-Qaeda in Iraq took responsibility for attacks earlier this month on three foreign embassies in Baghdad. Zebari told the Monitor that Iraqi intelligence failed to prevent the triple suicide bombing. He said the Interior Ministry had received information two days before that there were attacks planned on embassies but didn't reinforce security at foreign missions because they did not know which ones were being targeted.

More than 30 people were killed in the bombings near the German and Iranian embassies and the Egyptian consulate, including five police and diplomatic security guards. Zebari said the death toll at the Egyptian consulate would have been far higher had the guards not fired on the approaching vehicle, prompting it to detonate before it reached the building in Baghdad's upscale Mansour district.

The bombings were the latest in a series of coordinated Al Qaeda attacks aimed at destabilzing the government that began with the bombing of Zebari's own ministry last August.

"These people will continue to strike at the Shiite-Sunni divide to ignite sectarian tension, and with the political tension this is a viable way for the terrorists to exploit it," he said.

Meanwhile, Iraqi political parties are still awaiting certification of the election results in order to begin to form alliances for a coalition government. Some officials say that process could take as long as another four or five months.