Strikes by national unions in Guinea, declaration of martial law disrupting mining, exports of bauxite, will support spot alumina prices short-term at around $300/ton, says Citigroup's Alan Heap. Notes spot alumina has jumped to $350/ton from $200/ton in January on earlier general strike in Guinea, but end of strike at beginning of February was expected to pressure prices towards $250/ton, as market faced glut of alumina short-term. "Further strike action and the declaration of martial law now clearly threaten this outlook."