Iceland's supermarkets have seen sales jump following the collapse of the country's banking system as shoppers respond to concerns that food imports may dry up.

A spokesperson for supermarket group Bonus, part owned by Baugur, told just-food that food sales have "almost doubled" in the past week. "People are stocking up on essentials," the spokesperson observed.

The company declined to comment on stock levels or the possibility that food imports could decrease.

However, after the collapse of Iceland's three largest banks - Kaupthing Bank, Landsbanki Island and Glitnir Bank - and the drastic fall in the krona, suppliers are reportedly demanding payment in advance and are unwilling to accept payment in the local currency.

"The worry is that companies have insufficient funds to import goods," a spokesperson for the Icelandic Federation of Trade and Services explained. "We import a lot of food and because of the devaluation of the Icelandic kroner the price of food in Iceland will rise steeply. But hopefully the kroner will get stronger in the next few weeks. Its current value is ridiculous."

Iceland relies on imports for a majority of foods and only produces significant quantities of meat, fish and dairy products.