NEW YORK (Reuters) - Boeing Co. apologized on Friday for a mistakenly published advertisement for its V-22 Osprey aircraft showing troops dropping onto the roof of a mosque in what appears to be a simulated battle scene.

The ad, coming amid rising concern among Muslims over U.S. military action in Iraq and Afghanistan, prompted immediate complaints from the Council on American-Islamic Relations (CAIR), which demanded the withdrawal of the campaign.

But Boeing, which created the ad with partner Bell Helicopter, said publication was a "clerical error" by the National Journal, which ran the ad on September 24.

"We consider the ad offensive, regret its publication and apologize to those who like us are dismayed with its contents," said Mary Foerster, vice president at Boeing's defense unit, in a statement.

The ad "did not proceed through normal channels," Boeing said, and despite asking for it to be withdrawn and destroyed, was published in error.

The National Journal, a Washington government and policy magazine, admitted it made a clerical error and said it accepted full responsibility in a statement issued on Friday.

The furor comes only two days after the Pentagon finally approved full-rate production of the V-22 tiltrotor aircraft -- which takes off and lands like a helicopter but can fly like a plane -- after years of checkered development.

The ad shows troops rappelling down from an Osprey craft to the domed roof of a building labeled "Muhammad Mosque" in Arabic as smoke billows from a burned-out car nearby.

"It descends from the heavens. Ironically it unleashes hell," says the ad, published by Boeing and Bell Helicopter, a unit of Textron Inc., which jointly developed the Osprey.

The aircraft "delivers Special Forces to insertion points never thought possible," says the text of the ad.

A spokesman for CAIR said on Friday the group welcomed the companies' swift response, but would press the issue of how such an ad came to be created.

The group had earlier called on Boeing and Bell chiefs to withdraw the ad.

The ad "clearly portrays special forces assaulting a mosque, a structure dedicated to civilian worship purposes," said CAIR executive director Nihad Awad, in a letter to the two companies. "This gives the impression that 'the insertion points never thought possible' are Islamic places of worship."

Bell said it regretted any concern provoked by the ad, and it was looking into its "creative processes" to prevent a repeat.

"At the very first indication that this ad caused discomfort nearly a month ago, we immediately pulled the creative and replaced it with an alternative ad," said Bell vice president Michael Cox, in a statement. "Despite our directive to the National Journal to replace the ad, it was not replaced as requested, which resulted in its publication this week."