By Niala Boodhoo - Reuters

WASHINGTON - Two cultural advisers to the Bush administration have resigned in protest over the failure of U.S. forces to prevent the wholesale looting of priceless treasures from Baghdad's antiquities museum.

Martin Sullivan, who chaired the President's Advisory Committee on Cultural Property for eight years, and panel member Gary Vikan said they resigned because the looting should never have been allowed to happen.

"If we understood the value of Sumerian cuneiform tablets to our past, as we do with oil getting us somewhere in our cars, I don't think this would have happened," Vikan, director of the Walters Art Gallery in Baltimore, told Reuters on Thursday.

At the start of the U.S.-led campaign against Iraq, military forces quickly secured valuable oil fields.

Baghdad's museums, galleries and libraries are empty shells, destroyed in a wave of looting that erupted as U.S.-led forces ended Saddam Hussein's rule last week, although antiquities experts have said they were given assurances months ago from U.S. military planners that Iraq's historic artifacts and sites would be protected by occupying forces.

"It didn't have to happen," Sullivan told Reuters. "In a pre-emptive war that's the kind of thing you should have planned for." Sullivan sent his letter of resignation earlier this week.

The Iraqi National Museum held rare artifacts documenting the development of mankind in ancient Mesopotamia, one of the world's earliest civilizations. Among the museum collection were more than 80,000 cuneiform tablets, some of which had yet to be translated.

Professional art thieves may have been behind some of the looting, said leading archeologists gathered in Paris on Thursday to seek ways to rescue Iraq's cultural heritage.

Among the priceless treasures missing are the 5,000-year-old Vase of Uruk and the Harp of Ur. The bronze Statue of Basitki from the Akkadian kingdom is also gone, somehow hauled out of the museum despite its huge weight.

The White House repeated on Thursday that the looting was unfortunate but the U.S. military had worked hard to preserve the infrastructure of Iraq.

"It is unfortunate that there was looting and damage done to the museum and we have offered rewards, as Secretary Rumsfeld has said, for individuals who may have taken items from the museum to bring those back," White House spokeswoman Claire Buchan said in Crawford, Texas, where President Bush is spending a long Easter break.

FBI Director Robert Mueller added that the bureau was sending agents to Iraq to assist with criminal investigations and had issued Interpol alerts to all member nations regarding the potential sale of stolen artifacts.

"We recognize the importance of these treasures to the Iraqi people and as well to the world as a whole," Mueller said. "And we are firmly committed to doing whatever we can in order to secure the return of these treasures to the people of Iraq."

The president appoints the 11-member advisory committee, which works through the State Department to advise the executive office on the 1970 UNESCO Convention on international protection of cultural objects.