Greek banks are reporting withdrawals of €800m per day ahead of Sunday's election.
Many citizens fear will result in the country being forced out of the euro.
Retailers said some of the money was being used to buy pasta and canned goods in case of shortages.
Fears of returning to the drachma were fanned by rumours that a radical leftist leader may win the election.
The last published opinion polls showed the conservative New Democracy party, which backs the €130 billion bailout that is keeping Greece afloat, running neck-and-neck with the leftist SYRIZA party, which wants to cancel the rescue deal.