Anxious Greeks lined up outside ATMs after Prime Minister Alexis Tsipras made a surprise call for a referendum on austerity terms demanded by lenders, throwing talks with lenders in disarray and putting Greece on the verge of a default.
About 35 percent of the ATM network - some 2,000 out of the 5,500 ATMs across Greece - ran out of euro banknotes at one point during the day and were being replenished, the bankers said. Banks were working in coordination with the central bank to keep the network fed with cash, they said.
Replenishing ATMs usually takes one to two hours per ATM, leading to the long lines, one banking source said.
Around 600 million euros was withdrawn from the banking system on Saturday, one senior banker at one of Greece's four big lenders told Reuters. A second banker estimated the outflow at more than 500 million euros.