Iraq has obtained global positioning satellite scrambling devices that could play havoc with U.S. smart bombs, the Pentagon says, according to a Fox News Channel report.

According to the report, the GPS scramblers – about the size of a clock radio – have been positioned around the borders of Iraq in an effort to throw satellite-guided bombs away from targets.

In Desert Storm, guided ammunitions made up only 20 percent of the bombs dropped on Iraq. However, in the impending war, the Defense Department would rely heavily on the more accurate smart weapons.

Nearly 100 percent of the bombing sorties planned in an Iraq attack would be conducted using this newer technology, according to Pentagon sources. This has been made possible by a retrofit to existing "dumb" bombs – the Joint Direct Attack Munition, or JDAM. It screws onto the tail and around the belly of a conventional 1,000- or 2,000-pound unguided bomb, giving it far more precision even than the old laser-guided bombs of the Persian Gulf War.

GPS systems also are used to guide missiles to targets – including Cruise missiles.

Pentagon sources reportedly told Fox News Channel they were concerned about the GPS scrambling devices obtained by Iraq and were studying their options.