When President Bush used the same law to suspend the importation of several makes of assault-type rifles--including from dealers who already had been given permits--his action was challenged in court but the ban was sustained.
Administration officials cautioned that their main concern is the long-term policy goal of keeping such weapons off the nation's streets, saying that they do not want any short-term actions to jeopardize that. They stressed that the initial directive is only a temporary solution and that the real focus should be banning inappropriate weapons permanently.
Over the last year, the ATF has issued permits for about 600,000 weapons. However, the influx of weapons, while disturbing, is not as extensive as the permit numbers imply, officials cautioned. The permits are given for the maximum number of allowable weapons; actual imports usually fall far short of that, a Treasury official said. As of Monday there was no report that any of those 600,000 weapons had arrived. Importers have 15 days to report actually bringing the weapons into the country.
As for the 150,000 recently approved imports, Treasury officials said they would not specify the American or foreign dealers involved or the countries of origin because of proprietary concerns.
The WUM-1, for instance, can be ordered from gun magazines for $210.
Administration officials refused to speculate on a possible motive for ATF agents to have approved the import permits.
"I'd like to stay away from speculating on what might have been their reason," the senior Treasury official said. He added that, until the outcome of the internal review, he would also refrain from specifying whether one or several officials were responsible.
Times Washington Bureau Chief Doyle McManus contributed to this story.