The failure to find the missiles, which could number in the hundreds, is the main reason that the Baghdad International Airport remains closed to commercial traffic, officials in Baghdad told the Times.

US military officers do not know how many missiles are missing because they do not know how many there were in Saddam's arsenal.

But shoulder-fired missiles have already been fired unsuccessfully at incoming planes several times in recent weeks, one senior official told the newspaper, noting that most of the attacks have not been made public.

US officials are offering 500 dollars for each missile -- mostly Russian designed SA-7s -- that Iraqis hand in. Up to now 317 have been collected, while several hundred more have been found in ammunition dumps, the Times reports.

However an SA-7 can sell for some 5,000 dollars on the black market, according to the Times.

An SA-7 weighs about 13 kilos (30 pounds) and is less than two meters (six feet) long.

SPACE.WIRE