An Afghan resistance leader said Iran seized nine U.S.-made Stinger anti-aircraft missiles in a skirmish with Afghan guerrillas in late May. Yunis Khalis, who heads one of the main Muslim guerrilla groups fighting in Afghanistan, said that Iranian border guards seized the missiles when a five-truck arms convoy strayed into Iranian territory. Three trucks managed to escape, but the other two were seized by Iran. He said the Iranians later "offered us the rest of the weapons but not the Stingers." Defense Secretary Caspar W. Weinberger, in an Oct. 14 interview, said that Iran might have obtained a small number of the deadly missiles by taking them away from a U.S.-backed group of Afghan rebels.